Diagnostic Imaging
Námskeið LÆK207F Myndgreining. - Höfundur: Andrea G. Rockall Andrew Hatrick Peter Armstrong Martin Wastie
6.690 kr.
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- LÆK207F Myndgreining.
Annað
- Höfundur: Andrea G. Rockall Andrew Hatrick Peter Armstrong Martin Wastie
- Útgáfa:7
- Útgáfudagur: 03/2013
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- Format:ePub
- ISBN 13: 9781118524206
- Print ISBN: 9780470658901
- ISBN 10: 1118524209
Efnisyfirlit
- Front Matter
- Companion website
- Contents
- Preface
- Acknowledgements
- List of Abbreviations
- The Anytime, Anywhere Textbook
- Companion website
- Use of the imaging department
- Conventional radiography
- Box 1.1 Best practice when requesting imaging investigations
- Computed tomography
- Fig. 1.1 Principle of CT. The x-ray tube and detectors move around the patient enabling a picture of x-ray absorption in different parts of the body to be built up.
- Fig. 1.2 Scale depicting the CT density (Hounsfield units) of various normal tissues in the body.
- Fig. 1.3 Coronal reconstruction of CT of the chest, abdomen and pelvis. The images were obtained in the axial plane using very thin sections and then reconstructed into the desired plane – a coronal plane in this example. The illustrated section is through the posterior abdomen and shows the kidneys. There is a retroperitoneal mass (arrow) displacing the left kidney and causing hydronephrosis.
- Fig. 1.4 Shaded surface 3D CT reconstruction. The images can be viewed in any desired projection and give a better appreciation of the pelvis. Two fractures are demonstrated in the left innominate bone (arrows), which were hard to diagnose on plain film.
- Fig. 1.5 Effect of varying window width on CT. In (a) and (b) the level has been kept constant at 65 Hounsfield units (HU). The window width in (a) is 500 HU whereas in (b) it is only 150 HU. Note that in the narrow window image (b), the metastases are better seen, but that structures other than the liver are better seen in (a).
- Computed tomography angiography
- Artefacts
- Contrast agents in conventional radiography and computed tomography
- Ultrasound
- Fig. 1.6 Ultrasound scan of longitudinal section through the liver and right kidney. A cyst (C) is present in the upper pole of the kidney.
- Fig. 1.7 Ultrasound scan of gall bladder showing a large stone in the neck of the gall bladder (downward pointing arrow). Note the acoustic shadow behind the stone (horizontal double-headed arrow).
- Fig. 1.8 Ultrasound scan of pancreas showing a 1 cm tumour (T) (an insulinoma) at the junction of the head and body of the pancreas. Ao, aorta; Duo, duodenum; IVC, inferior vena cava; P, pancreas; SMA, superior mesenteric artery; SpV, splenic vein.
- Doppler effect
- Fig. 1.9 Principle of Doppler ultrasound. In this example, flowing blood is detected in a normal carotid artery in the neck. With blood flowing away from the transducer, the frequency of the received sound is reduced, whereas with blood flowing towards the transducer, the frequency of the received sound is increased. For anatomical images, the flowing blood is colour coded according to the direction of flow. (θ is the angle between the vessel and the transmitted sound wave: an angle known as the Doppler angle. The angle of the beam is indicated by the fine zig-zag line across the image.) The flow – velocity waveform has been taken from the gate within the artery. The peaks represent systolic blood flow.
- Fig. 1.10 Colour Doppler. (a) Normal renal artery. (b) Normal renal vein. (c) Bifurcation of the common carotid artery showing stenosis of the internal carotid artery. The flowing blood is revealed by colour. The precise colour depends on the speed and direction of the blood flow. cca, common carotid artery; eca, external carotid artery; ica, internal carotid artery.
- Box 1.2 Doppler frequency shift formula
- Fig. 1.11 Radionuclide bone scan. The patient has received an intravenous injection of a 99m Tc-labelled bone-scanning agent (a complex organic phosphate). This agent is taken up by bone in proportion to bone turnover and blood flow. The increased uptake in the femur in this patient was due to Paget’s disease.
- Positron emission tomography
- Fig. 1.12 FDG-PET scans, maximum intensity projections. (a) Normal isotope distribution. There is intense uptake in the brain and the neck uptake is in the tonsils. The FDG is excreted by the kidneys. (b) Lymphoma, showing multiple visceral, nodal, bone and scalp deposits.
- Fig. 1.13 FDG-PET/CT of lung cancer. (a) Coronal fused image and (b) maximum intensity projection, demonstrating a small left lung cancer (arrowed in (a)). The remainder of the FDG uptake is physiological.
- Table 1.1 Appearance of water and fat on different magnetic resonance sequences
- Fig. 1.14 MRI of brain. (a) Axial T1-weighted image. (b) Axial T2-weighted image. (c) Axial T1-weighted image following gadolinium. Note that the cerebrospinal fluid within the lateral ventricles is of low signal intensity on T1-and high signal intensity on T2-weighted images (arrows in (a) and (b)). Note also that the intensity of the white and grey matter of the brain differs on the two images. There is a metastasis from a breast carcinoma (M) in the right occipital pole, showing oedema around the mass on the T2-weighted image and enhancement on the post contrast image.
- Fig. 1.15 Diffusion-weighted imaging. (a) A diffusion-weighted image with b value 750 demonstrating a small cervix cancer with high signal intensity (arrow). (b) The corresponding apparent diffusion coefficient (ADC) map demonstrates low signal intensity at the same position (arrow). This combination of high signal intensity on the high b value image and low signal intensity on the ADC map is consistent with restricted water diffusion, a characteristic feature of many cancers.
- Fig. 1.16 Diagram of an MRI machine. The patient lies within a strong magnet (usually a cylindrical magnet). The radiofrequency transmitter coils send radiowaves into the patient and the same coils receive signals from within the patient. The intensity and source of these signals can be calculated and displayed as an image.
- Fig. 1.17 MRI of a sagittal section of lumbar spine. (a) On this T1 sequence, the spinal cord is grey, cerebrospinal fluid (CSF) is nearly black and subcutaneous fat is white. (b) T2-weighted sequence. Here the CSF is white. Cortical bone (arrows) returns no signal and appears as a black line on both sequences. The fat in the bone marrow produces a signal that enables the vertebrae to be visualized.
- Fig. 1.18 MRI of brain showing an arteriovenous malformation (arrow) in the right cerebral hemisphere. The fast-flowing blood in the malformation is responsible for the absence of signal (signal void). The image is a T2-weighted image, and is normal apart from the arteriovenous malformation and its consequences.
- Contrast agents for magnetic resonance imaging
- Fig. 1.19 Magnetic resonance angiogram of the intracranial arteries. No contrast medium was used to obtain this image. ac, anterior cerebral; ic, internal cerebral; mc, middle cerebral; pc, posterior cerebral; pcom, posterior communicating artery.
- THORACIC DISEASE
- Imaging techniques
- Plain chest radiograph
- Fig. 2.1 Normal chest. (a) Posteroanterior view. The arrows point to the breast opacities of this female patient. (b) Lateral view. The vertebrae are more transradiant (i.e. blacker) as the eye travels down the spine, until the diaphragm is reached. Ao, aorta; T, trachea.
- Fig. 2.2 Effect of expiration on chest films showing two films of the same patient taken one after the other. (a) Expiration. (b) Inspiration. On expiration the heart appears larger and the lung bases are hazy.
- Trace the diaphragm
- Check the size and shape of the heart
- Fig. 2.3 Normal but prominent thymus in a child aged 3 months. The thymus shows the characteristic ‘sail shape’ projecting to the right of the mediastinum (arrows). This appearance should not be confused with right upper lobe consolidation or collapse.
- Check the position of the heart and mediastinum
- Look at the mediastinum
- Examine the hilar structures
- Examine the lungs
- Fig. 2.4 Position of the lobes and fissures. (a) The oblique (major) fissure is similar on the two sides. The oblique fissures are not visible on the frontal view; their position is indicated by dashed lines. (b) In the left lung the oblique fissure separates the upper lobe (UL) and lower lobe (LL). (c) In the right lung, there is an extra fissure – the horizontal (minor) fissure, which separates the upper lobe (UL) and middle lobe (ML). (The lingular segments of the upper lobe are analogous to the segments of the middle lobe.) T, trachea.
- Fig. 2.5 The azygos lobe fissure. During normal intrauterine development the azygos vein migrates through the lung from the chest wall to lie within the mediastinum. (a) CXR in a patient with an azygos ‘lobe’, the vein (large arrow) fails to reach the tracheobronchial angle and, therefore, lies in the lower end of the azygos fissure (small arrows). (b) CT in the same patient. The azygos fissure can be clearly seen (small arrow). This variant is of no clinical significance.
- Check the integrity of the ribs, clavicles and spine and examine the soft tissues
- Assess the technical quality of the film
- Computed tomography
- Technique
- Fig. 2.6 Chest CT illustrating the different window centres (levels) used for the lungs and mediastinum. (a) Lung settings. A negative centre (minus 700 Hounsfield units [HU]) and a wide window width (1000 HU) shows the lungs to advantage, but there is no detail of mediastinal structures, the mediastinum being uniformly white. In this example, the lung vessels are the only identifiable opacities originating from within the lung. Note the peripheral left lung cancer (arrow). (b) Mediastinal settings. A centre close to average soft tissue density (40 HU) and a narrow window width (400 HU) shows the structures within the mediastinum clearly, but the lungs are blacked out. The lung cancer is arrowed.
- Indications
- Fig. 2.7 Aortic aneurysm. (a) Example of the use of contrast-enhanced CT to diagnose an aortic aneurysm. The lumen of the aneurysm (*) enhances brightly. Much of the aneurysm is lined by clot. (b) The CXR shows a mass (arrows), but the precise diagnosis of aortic aneurysm cannot be made.
- Normal images
- Fig. 2.8 Lung nodule (arrow) on (a) thin (0.6mm) and (b) thick (11mm) maximum intensity projection (MIP) images. On the thick MIP image, the nodule can clearly be identified separate from the adjacent branching vessels.
- Technique
- Plain chest radiograph
- Magnetic resonance imaging
- Radionuclide lung scanning
- Fig. 2.9 (a) Normal radionuclide perfusion scan (posterior view) using 99m Tc-labelled macroaggregates of albumin. (b) Normal radionuclide 81mKr ventilation scan (posterior view).
- Positron emission tomography
- Fig. 2.10 FDG-PET scan of the chest and abdomen showing a focus of high activity in a lung cancer (large arrow) and mediastinal lymph node metastasis (small arrow). (a) Maximum intensity projection (MIP). (b) Coronal fused PET/CT. (c) Axial fused PET/CT. No other abnormality is seen on any of the images. High activity in the myocardium, kidneys and bladder is normal.
- Ultrasound
- Fig. 2.70 Normal transoesophageal echocardiogram showing a normal descending aorta (A).
- Fig. 2.71 (a) Transoesophageal echocardiogram showing the true (T) and false (F) lumina in the descending aorta. (b) CT showing the displaced intima separating the true and false lumina in the ascending and descending aorta.
- Imaging techniques
- Obstructive airways disease
- Small lesions
- Pulmonary emboli without infarction
- Infections
- Diffuse pulmonary fibrosis
- Pleural abnormality
- Mediastinal masses
- Fig. 2.11 (a) Extrapleural mass. The mass has a smooth convex border with a wide base on the chest wall (a myeloma lesion arising in a rib). This shape is quite different from a peripherally located pulmonary mass such as a primary carcinoma of the lung (b).
- Fig. 2.12 The silhouette sign. (a) The left heart border is invisible because it is in contact with consolidation in the adjacent lingula. (b) The left heart border can be seen because the consolidation is in the left lower lobe and air in the lingula preserves the visibility of the cardiac silhouette (arrows). Note that now it is the diaphragm outline that is invisible. (c) A side view diagram of the lung explaining the relationship of the lingula and lower lobes to the heart and diaphragm.
- Air-space opacification
- Fig. 2.13 Air-space filling. In this case, the consolidation in the right upper lobe is due to pneumonia.
- Fig. 2.14 The air bronchogram sign. An extensive air bronchogram is seen in this patient with pneumonia. The arrow points to a bronchus that is particularly well seen.
- Fig. 2.15 The air bronchogram sign. CT showing an air bronchogram in an area of pulmonary consolidation from pneumonia.
- Box 2.1 Radiological signs of lung disease
- Fig. 2.16 Consolidation of the right lower lobe. Note the application of the silhouette sign here. (a) Posteroanterior view. The heart border and the medial half of the right hemidiaphragm are visible, whereas the lateral half is invisible. (b) On the lateral view, the oblique fissure forms a well-defined anterior boundary and the right hemidiaphragm is ill defined. Only the left hemidiaphragm is seen clearly.
- Fig. 2.17 Patchy consolidation in both lower lobes in a patient with bronchopneumonia.
- Fig. 2.18 Cavitation in staphylococcal pneumonia. (a) A round area of consolidation which, 7 days later (b) shows central translucency due to the development of cavitation.
- Fig. 2.19 Fluid level (arrowheads) in a lung abscess. Fluid levels are only visible if the chest radiograph is taken with a horizontal x-ray beam.
- Fig. 2.20 Bacterial lung abscess shown by CT on (a) mediastinal and (b) lung windows. Note the thick-walled, air-filled cavity. The abscess is arrowed in (a).
- Pulmonary collapse (atelectasis)
- Collapse caused by bronchial obstruction
- Fig. 2.21 Collapse of the right lower lobe. (a) Posteroanterior and (b) lateral views. In this example the apical segment is relatively well aerated.
- Fig. 2.22 Collapse of the middle lobe. (a) Posteroanterior and (b) lateral views. The collapsed lobe is most obvious on the lateral view (arrows). Note the silhouette sign obliterating the lower right heart border.
- Fig. 2.23 Collapse of the right upper lobe. (a) Posteroanterior and (b) lateral views. Note the opacification in the right apex and elevated horizontal fissure.
- Fig. 2.24 Collapse of the left upper lobe. (a) Posteroanterior and (b) lateral views. Note the veil-like opacity of the left hemithorax on the PA view. The lower border of the collapsed lobe is ill defined. The upper two-thirds of the left mediastinal and heart borders are invisible, but the aortic knuckle and descending aorta are identifiable. The visible portions of the aorta have been drawn in for greater clarity. On the lateral view, the upper lobe can be seen collapsed anteriorly.
- Fig. 2.25 Collapse of the left lower lobe. (a) Chest radiograph. The triangular opacity of the collapsed lobe is seen through the heart. Its lateral border is formed by the displaced oblique fissure (arrows). (b) CT. The collapsed lobe is seen lying posteriorly in the left thorax. The well-defined anterior margin is due to the displaced oblique fissure (arrows).
- Fig. 2.26 CT of a severely collapsed right upper lobe. Note the smooth lateral border of the collapsed lobe formed by the displaced oblique (major) fissure (arrow). The scan shows compensatory overexpansion of the left upper lobe, which has crossed the midline anterior to the aortic arch (A). The superior vena cava is highlighted with an asterisk.
- Fig. 2.27 Collapse of the left lung showing tracheal and mediastinal displacement.
- Collapse in association with pneumothorax or pleural effusion
- Fig. 2.28 CT showing pleural effusion and pulmonary collapse. The collapsed lobe (arrows) can be clearly seen beneath the large left pleural effusion.
- Linear atelectasis
- Fig. 2.37 Band-like opacity in the right lower lobe caused by discoid atelectasis.
- Collapse caused by bronchial obstruction
- Fig. 2.29 Solitary spherical opacity. (a) The large size and the irregular infiltrating edge are important diagnostic features suggesting primary carcinoma of the lung. (b) The small size and relatively smooth border leads to a wider differential diagnosis. In this case the diagnosis was bronchial carcinoid. (c) Typical bronchial carcinoma on CT showing an infiltrating edge.
- Box 2.2 Causes of a solitary pulmonary nodule
- Comparison with previous films
- Calcification
- Fig. 2.30 Calcification in a pulmonary hamartoma. The central flocculant (‘popcorn’) calcification is typical of that seen in hamartomas.
- Fig. 2.31 Benign patterns of calcification. (a) A small calcified nodule (arrow). The calcific density of this fungal granuloma is clearly shown by CT. (b) ‘Popcorn’ calcification (arrow) in an unusually large hamartoma. The calcification was difficult to appreciate on CXR.
- Involvement of the adjacent chest wall
- Fig. 2.32 CT showing a cavitating lung cancer with local invasion of the chest wall and erosion of the cortex of the adjacent rib (arrow).
- Shape of the opacity
- Fig. 2.33 Outlines of different primary carcinomas of the lung.
- Cavitation
- Fig. 2.34 CT of cavitating primary carcinoma of the lung. The variable thickness of the cavity wall is a striking feature. The air – fluid level is also well seen (arrow).
- Size
- Other lesions
- Role of computed tomography
- Table 2.1 Recommendations for follow-up and management of nodules smaller than 8 mm detected incidentally at non-screening CT: Fleishner guidelines
- Role of positron emission tomography
- Fig. 2.35 FDG-PET imaging in a solitary pulmonary nodule. (a) The chest radiograph shows an ill-defined nodule. (b) CT shows a rounded nodule with a spiculated outline. (c) The PET scan shows substantial activity in the nodule (the myocardial activity is normal). The diagnosis was bronchial carcinoma.
- Role of needle biopsy
- Multiple pulmonary nodules
- Fig. 2.115 Pulmonary metastases. (a) There are numerous rounded opacities of varying sizes in both lungs. (b) Axial and (c) coronal reformatted CT in the same patient demonstrating the well-defined metastases, in this case from a testicular tumour.
- Septal lines
- Fig. 2.36 Septal (Kerley B) lines in a patient with pulmonary oedema. The septal lines (arrow) are seen in the outer centimetre of lung where blood vessels are invisible or very difficult to identify.
- Pleuropulmonary scars and linear (discoid) atelectasis
- Emphysematous bullae
- Fig. 2.38 Linear opacities caused by walls of bullae (blebs). The bullae are air-spaces devoid of blood vessels.
- Pleural edge in a pneumothorax
- Fig. 2.39 Nodular opacitying in the lung of a patient with miliary tuberculosis.
- Fig. 2.40 (a) Reticulonodular opacitying in the lung of a patient with fibrosing alveolitis. (b) HRCT of a different patient with cryptogenic (idiopathic) fibrosing alveolitis showing the honeycomb pattern to advantage.
- How to decide whether or not multiple, small pulmonary opacities are present on a chest radiograph
- High resolution computed tomography
- Table 2.2 Commoner causes of nodular and reticular shadowing on chest radiographs and high resolution computed tomography (HRCT)
- Multiple ring opacities of 1cm or larger
- Fig. 2.41 Ring opacities in bronchiectasis. Each ring opacity represents a dilated bronchus. A fluid level in one of the dilated bronchi is arrowed.
- Widespread small pulmonary calcifications
- Fig. 2.53 Pneumothorax. The pleural edge is arrowed. The diagnosis of pneumothorax requires the identification of this edge and a clear space beyond it.
- Fig. 2.54 Tension pneumothorax. The left hemidiaphragm is depressed and the mediastinum is shifted to the right. The left lung (arrows) is substantially collapsed and demonstrates increased density.
- Fig. 2.42 Inhaled foreign body causing check valve obstruction of the left main bronchus. Note the increased transradiancy of the left lung, and the slight displacement of the heart to the right. (The film was exposed in expiration.)
- Pleural effusion
- Fig. 2.43 Large left pleural effusion. The opacity of the pleural fluid is entirely homogeneous and lies outside the lung edge. The fluid appears higher laterally than medially, a point that can be useful in differentiating pleural fluid from pulmonary opacities. The trachea and heart are slightly displaced to the right.
- Fig. 2.44 Large right subpulmonary effusion (the patient has had a right mastectomy). Almost all the fluid is between the lung and the diaphragm. The right hemidiaphragm cannot be seen, but its estimated position has been pencilled in.
- Fig. 2.45 CT of pleural fluid. The bilateral pleural effusions are of homogeneous density, with a CT number between zero and soft tissue. The well-defined meniscus-shaped border with the adjacent lung is typical. The right-sided effusion is causing a little compression collapse of the underlying lung (which shows contrast enhancement).
- Fig. 2.46 Pleural effusion. (a) CT. The section is taken through the lowermost portion of the pleural cavity and at this level the distinction from ascites is a potential problem because the diaphragm itself is not visible. Pleural fluid, as here, is not affected by the peritoneal reflections of the bare area (see Fig. 10.1). (b) Ultrasound, sagittal image. The pleural effusion is seen as a transonic area between the diaphragm (downward pointing arrow) and adjacent lung (upward pointing arrow).
- Fig. 2.47 Loculated pleural fluid. (a) Posteroanterior and (b) lateral views showing an empyema loculated against the posterior chest wall. (c) Fluid loculated in the horizontal (minor) fissure in another patient. Both these fluid collections could be confused with an intrapulmonary mass.
- Fig. 2.48 Loculated pleural fluid (empyema). (a) Plain chest film showing the fluid loculated in the horizontal (minor) fissure. (b) Chest ultrasound in a different patient, demonstrating multiple septations (arrows) within the pleural fluid. (c) CT scan in a similar patient clearly shows the characteristic shape and location of two loculated pleural fluid collections (larger one posteriorly and a smaller one anteriorly [arrow]).
- Fig. 2.49 Empyema. (a) CT showing a typical lens-shaped pleural fluid collection with a clearly marginated wall consisting of thickened pleura. (b) CT showing multiple loculated air collections within the pus.
- Plain radiographic findings
- Ultrasound
- Computed tomography
- Pleural thickening (pleural fibrosis)
- Fig. 2.50 Pleural thickening. (a) CXR in a patient who been treated for a tuberculous pleural effusion that had resolved leaving pleural thickening, which obliterated the left costophrenic angle. (b) CXR showing calcifled pleural plaques in a different patient with previous asbestos exposure. The extensive calcification is usually best appreciated along the lateral chest wall or over the diaphragms. When seen on an AP film, the en face plaques are said to have a ‘holly-leaf pattern’ of calcification.
- Pleural tumours
- Fig. 2.51 Metastatic disease of the pleura. (a) CXR and (b) CT in a patient with breast cancer showing diffuse thickening of the pleura on the right, secondary to metastatic disease. Note the absence of the left breast shadow due to a previous mastectomy on the CXR.
- Pleural calcification
- Fig. 2.52 Unilateral pleural calcifications from old tuberculous empyema.
- Pneumothorax
- Hydropneumothorax, haemopneumothorax and pyopneumothorax
- Fig. 2.55 Hydropneumothorax. The arrows point to the air – fluid level in the pleural space. In this case, the edge of the lung is difficult to see on the PA view; most of the fluid and air were loculated posteriorly.
- Hydropneumothorax, haemopneumothorax and pyopneumothorax
- Fig. 2.56 The anterior (A), middle (M) and posterior (P) compartments of the mediastinum. The divisions are arbitrary and do not correspond to those used by anatomists. The anterior mediastinum refers to the structures anterior to the trachea and the major bronchi. The posterior mediastinum refers to structures posterior to a line joining the anterior boundary of the vertebral bodies.
- Fig. 2.57 The causes of mediastinal masses divided according to location. Note that both lymphadenopathy and aortic aneurysms occur in all three major compartments.
- Fig. 2.58 Anterior mediastinal mass. (a) Posteroanterior and (b) lateral views. There is a large mass situated anteriorly in the mediastinum projecting to the left side which was due to a mass of lymph nodes involved by malignant lymphoma. Diagnosing the anterior location of the mass depends on noting the density of the retrosternal areas. This area should normally have the same density as the retrocardiac area.
- Computed tomography and magnetic resonance imaging of the normal mediastinum
- Fig. 2.59 CT of the normal mediastinum and corresponding line drawings. The levels at which the four selected levels were taken are shown in the diagrams below. Intravenous contrast has been given; it is particularly concentrated in the right brachiocephalic vein and superior vena cava. Air is present in the oesophagus, which can be a normal finding. LCCA, left common carotid artery; LMB, left main bronchus; LSA, left subclavian artery; RBCA, right brachiocephalic (innominate) artery; RMB, right main bronchus.
- Fig. 2.60 MRI of the normal mediastinum (T1-weighted, cardiac gated). (a) Axial scan through the level of the pulmonary hila. (b) Higher axial section through the level of the aortic arch. (c) Coronal scan. Ao, aorta; Br, bronchi; LPA, left pulmonary artery; LV, left ventricle; MPA, main pulmonary artery; RA, right atrium; RPA, right pulmonary artery; SVC, superior vena cava; T, trachea.
- Mediastinal masses
- Plain chest films
- Fig. 2.61 Retrosternal goitre. (a) CXR showing a large, right-sided, superior mediastinal mass displacing the trachea. (b) CT in the same patient showing the heterogeneously enhancing mass (arrow) to the right of the trachea (*).
- Fig. 2.62 (a) CXR and (b) CT in a patient with an incidental mediastinal mass, shown to represent a bronchogenic cyst (arrow). Note the bilateral breast implants on the CT.
- Fig. 2.63 Superior mediastinal mass. CXR showing lymph node enlargement. Note the bilateral lobular masses.
- Fig. 2.64 Hiatus hernia. (a) Lateral and (b) posteroanterior chest films showing characteristic retrocardiac density containing an air – fluid level (arrows).
- Fig. 2.65 Fat pads in both cardiophrenic angles. Note the loss of clarity of the adjacent cardiac outline – an example of the silhouette sign. The anterior location was confirmed on the lateral view.
- Computed tomography
- Fig. 2.67 Extensive mediastinal lymphadenopathy (caused by lymphoma) shown by CT.
- Fig. 2.66 Neurofibroma in the posterior mediastinum. MRI showing the neurofibroma (arrows) lying against the spine, but not growing into the spinal canal.
- Fig. 2.68 Thymoma. CT showing a large, lobulated, anterior mediastinal mass with punctuate calcification (arrow), which proved on resection to be a thymic tumour.
- Plain chest films
- Fig. 2.69 CT showing an aneurysm of the descending aorta. The lumen has been opacified by intravenous contrast enhancement. The unopacified component is clot lining the aneurysm.
- Fig. 2.72 Pneumomediastinum showing air (arrows) in the mediastinum extending up into the neck. (a) Posteroanterior and (b) lateral views.
- Fig. 2.73 Lobulated mass at the left hilum from enlarged lymph nodes. The right hilum is normal. The lymphadenopathy in this case was due to metastases from a bronchial carcinoma (not visible on this image) in the left lower lobe.
- Fig. 2.74 Enlargement of the hilar arteries in a patient with severe pulmonary hypertension. Note that the heart and the main pulmonary artery are also enlarged and that the hilar opacities branch in the manner expected of arteries.
- Lymph node enlargement
- Fig. 2.75 Bilateral hilar adenopathy. The enlarged hila are lobular in outline and dense. The diagnosis in this patient was sarcoidosis.
- Box 2.3 Causes of hilar enlargement
- Fig. 2.87 Sarcoidosis. CT scan showing bilateral hilar (long arrows) and subcarinal (short arrow) lymphadenopathy.
- Neoplasm
- Fig. 2.76 Localized eventration of the diaphragm. There is a smooth localized elevation of the medial half of the right hemidiaphragm (arrows). On the lateral view, the eventration involved the anterior half of the right hemidiaphragm.
- Chest wall
- Fig. 2.77 Soft tissue swelling associated with a rib lesion. In this patient with myeloma in a rib, the soft tissue swelling is more obvious than the rib destruction. The bone between the two arrows has been destroyed. This important sign could be easily overlooked unless special attention is paid to identifying rib destruction in the region of soft tissue swelling.
- Bacterial pneumonia
- Fig. 2.78 Bilateral bronchopneumonia. There is widespread bilateral patchy consolidation.
- Viral and mycoplasma pneumonia
- Fig. 2.79 Viral pneumonia, showing widespread, ill-defined, small areas of consolidation in both lungs.
- Lung abscess
- Pulmonary tuberculosis
- Primary tuberculosis
- Fig. 2.80 Tuberculosis. (a) The primary complex. This 7-year-old child shows ill-defined consolidation in the right lung together with enlargement of the draining lymph nodes (arrow). (b) Miliary tuberculosis. The innumerable small nodular opacities uniformly distributed throughout the lungs in this young child are typical of miliary tuberculosis. In this instance, no primary focus of infection is visible.
- Postprimary tuberculosis
- Fig. 2.81 Postprimary tuberculosis. (a) There are ill-defined consolidations scattered in both upper lobes; their size and distribution should suggest the diagnosis of postprimary tuberculosis. (b) The right upper lobe is consolidated and contains a large central cavity. Patchy consolidation from tuberculous bronchopneumonia is seen in the right mid and lower zones and in the left upper zone.
- Fig. 2.82 Mediastinal lymphadenopathy (arrows) caused by tuberculosis.
- Fig. 2.83 Old calcified tuberculous disease. There are numerous foci of calcification in both lungs. The right upper lobe shows extensive fibrosis and bullae. There was no evidence in this patient that active infection was present. However, given this film in isolation, active disease could not be excluded.
- Tuberculoma
- Mycetoma
- Fig. 2.84 Mycetoma. (a) Plain film in a pre-existing old tuberculous cavity, the wall of which is arrowed. The fungus ball moved around the cavity when the patient was placed on his side. (b) CT in a pre-existing old tuberculous cavity. M, mycetoma.
- Is the tuberculosis active?
- Primary tuberculosis
- Fig. 2.85 Fungus infection. (a) CXR in a patient from southeast USA. The cavity (arrow) was due to North American blastomycosis. Note the similarity to tuberculosis. Other fungi, e.g. histoplasmosis, can give an identical appearance. (b) CT (lung windows) in an immunocompromised patient following chemotherapy for metastatic prostate cancer. The CT shows a more diffuse pattern of fungal infiltration in the lungs (white arrows). Note the sclerotic bone metastasis (black arrow).
- Hydatid disease
- Fig. 2.86 Pneumocystis carinii pneumonia in AIDS. (a) Chest x-ray showing typical widespread, low density air-space opacity. (b) HRCT in another patient with similar but less advanced changes.
- Fig. 2.88 Late fibrotic stage of sarcoidosis. The dense reticulonodular opacitying radiates outwards from the hila, maximally in the mid and upper zones. Enlarged lymph nodes are still visible at the hila and in the right paratracheal region. Many patients with this degree of pulmonary fibrosis from sarcoidosis do not have visibly enlarged lymph nodes.
- Usual interstitial pneumonia (cryptogenic fibrosing alveolitis, idiopathic pulmonary fibrosis)
- Fig. 2.89 Idiopathic UIP. (a) CXR showing reticulonodular opacitying (honeycomb lung) with basal predominance. Scleroderma, rheumatoid arthritis and drug-induced interstitial fibrosis give a similar picture. (b) HRCT showing the typically subpleural honeycomb distribution in the lungs. (c) Note also the small peripheral nodule in the right lung (arrow), which on FDG-PET/CT was confirmed to represent a lung cancer, which has a higher incidence in these patients.
- Determining the cause of diffuse pulmonary fibrosis
- Fig. 2.92 Progressive massive fibrosis. Note the large oval opacities in the upper halves of both lungs. A nodular pattern is present elsewhere in the lung fields.
- Fig. 2.90 Postradiation fibrosis. The patient had received radiation therapy for a carcinoma in the right upper lobe. Notice the geometric outline to the opacitying corresponding to the radiation field, the resulting mediastinal deviation and distortion of the pulmonary vessels.
- Fig. 2.91 CT in a patient treated with radiation therapy for lymphoma. Note the linear fibrosis (arrows) in the lungs on either side of the mediastinum.
- Rheumatoid lung
- Systemic lupus erythematosus
- Scleroderma and dermatomyositis
- Wegener’s granulomatosis
- Coal workers’ pneumoconiosis
- Asbestos-related disease
- Fig. 2.93 CT showing extensive calcified pleural plaques in both hemithoraces, circumferentially around both lower lobes.
- Asthma
- Bronchiolitis
- Acute bronchitis
- Chronic obstructive pulmonary disease
- Chronic bronchitis and emphysema
- Fig. 2.94 Panacinar emphysema. (a) The diaphragm is low and flat and the ribs are widely spaced, indicating overinflation of the lungs. The peripheral vessels in most of the left lung and the upper half of the right lung are small and attenuated, indicating lung destruction. (b) CT showing innumerable bullae.
- Bronchiectasis
- Fig. 2.95 Bronchiectasis. Plain film showing a mixture of saccular and tubular bronchiectasis. The branching ectatic bronchi resemble large blood vessels but should not be confused with them.
- Fig. 2.96 Bronchiectasis. HRCT showing thick-walled, dilated bronchi crowded together in the left lower lobe. The normal appearance is seen in the right lower lobe.
- Chronic bronchitis and emphysema
- Fig. 2.97 Cystic fibrosis in a 14-year-old child. There is bronchial wall thickening, ring opacities of bronchiectasis and widespread ill-defined opacitying. All these phenomena tend to be maximal in the mid and upper zones. The diaphragm is somewhat low from obstructive airways disease.
- Fig. 2.98 Neonatal respiratory distress syndrome (hyaline membrane disease). Posteroanterior film showing the general granular opacity of the lungs typical of hyaline membrane disease. The vessels, the heart borders and the diaphragm outlines are indistinct and air bronchograms are visible. Note the uniformity of distribution of the changes in the lungs – an important diagnostic feature of hyaline membrane disease.
- Fig. 2.99 Meconium aspiration. This baby born at term had fetal distress during delivery and was born through meconium-stained liquor. The film shows patchy consolidations rather than the uniform changes seen in hyaline membrane disease. The diaphragm is lower than normal in position, which is another differentiation from hyaline membrane disease.
- Fig. 2.100 Adult respiratory distress syndrome. There is widespread air-space opacitying in the lungs.
- Plain film abnormalities
- Radionuclide lung scans
- Fig. 2.101 Matched ventilation/perfusion defects. 99mTc macroaggregate perfusion scan (a) showing matched defects when compared to the 81mKr ventilation scan (b). Both are anterior scans. The patient had widespread emphysema.
- Fig. 2.102 Pulmonary emboli. (a) 99mTc macroaggregate perfusion scan (posterior view) showing multiple wedge-shaped defects. The more obvious ones have been arrowed. (b) The ventilation scan, using 81mKr (also a posterior view), is normal. (c) CT pulmonary angiogram showing bilateral filling defects due to emboli in the central pulmonary arteries (arrow).
- Computed tomography pulmonary angiography
- Fig. 2.103 Pulmonary contusion from a gunshot wound. The ill-defined consolidation represents haemorrhage and oedema in the right upper lobe. The deformed metallic fragments of the bullet are clearly visible.
- Fig. 2.104 Rupture of the diaphragm. Coronal reformatted CT showing rupture of the left hemidiaphragm and resultant herniation of the stomach (S) and abdominal fat into the chest (arrow).
- Signs of a central tumour
- Fig. 2.105 Right hilar mass due to carcinoma of the bronchus. There is also a patch of consolidation in the right upper lobe laterally, from the central obstruction.
- Fig. 2.110 Mediastinal invasion. Contrast-enhanced CT showing extensive tumour in the mediastinum, compressing the left pulmonary artery and causing left upper lobe collapse. Ao, aorta; Br, bronchus; LPA, left pulmonary artery; SVC, superior vena cava.
- Signs of a peripheral tumour
- Fig. 2.106 Appearance of peripheral lung carcinoma. A lobulated mass (a) and a cavitating mass (b) are shown on plain films. (c) A spiculated mass is shown on CT.
- Fig. 2.107 Typical appearance and small size of a carcinoma of the bronchus discovered incidentally at CT.
- Spread of bronchial carcinoma
- Fig. 2.108 CT scan of a greatly enlarged lymph node (arrows). Note that the primary tumour lying posteriorly in the right lung has invaded the chest wall and partially destroyed the adjacent rib.
- Fig. 2.109 MRI (T1-weighted) showing enlarged node (arrows) which stands out clearly against the background of no signal in the lung, trachea and aorta.
- Fig. 2.111 Pancoast’s tumour. (a) CXR showing a carcinoma arising at the apex of the right lung (arrow) that has invaded and destroyed the adjacent ribs and spine. (b) CT scan in the same patient demonstrating the bony invasion far more clearly.
- Fig. 2.112 Pancoast’s tumour. The carcinoma of the lung can be seen invading the root of the neck on this coronal MRI T1-weighted scan.
- Fig. 2.113 Lymphangitis carcinomatosa. (a) There is widespread, ill-defined pulmonary opacitying with numerous septal lines. (b) The magnified view of the right lung base shows the septal (Kerley B) lines to advantage.
- Fig. 2.114 Lymphangitis carcinomatosa. The widespread connecting lines representing irregularly thickened interlobular septa are very well shown by HRCT. This appearance is virtually pathognomonic of lymphangitis carcinomatosa.
- Pulmonary metastases
- Pleural metastases
- Metastases to ribs
- Fig. 2.116 (a) CT in a patient with metastatic renal cancer, and (b) FDG-PET/CT in a different patient, demonstrating a large focal pleural deposit.
- Fig. 2.117 (a) Lymphoma involving the lung. The extensive pulmonary consolidations were due to neoplastic involvement. Pneumonia can give a similar appearance. (b) CT in a patient with primary pulmonary lymphoma showing more nodular opacities.
- Imaging techniques
- Box 3.1 Diagnostic information provided by cardiac imaging
- Plain chest radiography
- Heart size and shape
- Fig. 3.1 Outline of the heart in posteroanterior and lateral views. Ao, aorta; LA, left atrium; LAA, left atrial appendage; LV, left ventricle; PA, pulmonary artery; RA, right atrium; RPA, right pulmonary artery; RV, right ventricle.
- Fig. 3.2 Measurement of heart size. The transverse diameter of the heart is the distance between the two vertical tangents to the heart outline. When the cardiothoracic ratio (CTR) is calculated, the transverse diameter of the heart (B) is divided by the maximum internal diameter of the chest (A).
- Fig. 3.3 Pectus excavatum. (a) Posteroanterior view. Note how the heart is displaced and altered in shape by the depressed sternum. (b) Lateral film. The edge of the sternum has been traced in on this film. There was no cardiac disease in this patient.
- Fig. 3.4 Left atrial enlargement in a patient with mitral valve disease showing the ‘double contour sign’ (the left atrial border has been drawn in) and dilatation of the left atrial appendage (arrow).
- Fig. 3.5 Pericardial effusion. The heart is greatly enlarged. (Three weeks before, the heart had been normal in shape and size.) The outline is well defined and the shape globular. The lungs are normal. The cause in this case was a viral pericarditis. This appearance of the heart, though highly suggestive of pericardial effusion is not specific to it – a similar appearance can be seen with other causes of cardiac enlargement, e.g. cardiomyopathy.
- Main pulmonary artery and pulmonary vasculature
- Fig. 3.6 Enlarged main pulmonary artery in a patient with pulmonary valve stenosis. The bulge of the main pulmonary artery (lower arrow) is clearly greater than normal and at first glance one might be deceived into diagnosing enlargement of the aorta. However, the aortic knuckle is the first ‘bump’ on the left mediastinal border (upper arrow). It projects 2.5–3 cm lateral to the trachea. The pulmonary artery forms the segment immediately below the aortic knuckle.
- Increased pulmonary blood flow due to left to right shunts
- Fig. 3.7 Ventricular septal defect in a child. The heart is enlarged and there is obvious enlargement of the pulmonary vessels. The left to right shunt in this case was 3 : 1.
- Box 3.2 Causes of pulmonary arterial hypertension
- Pulmonary arterial hypertension
- Fig. 3.8 Right ventricular enlargement in an adult with primary pulmonary hypertension. The heart is enlarged with the apex of the heart somewhat lifted off the diaphragm. Note also the features of pulmonary arterial hypertension – enlargement of the main pulmonary artery and hilar arteries with normal vessels within the lungs.
- Pulmonary venous hypertension
- Fig. 3.9 Pulmonary venous hypertension in a patient with mitral valve disease. The upper zone vessels (straight arrows) are larger than the equivalent vessels in the lower zones (curved arrows). This is the reverse of the normal situation. (The left atrial border has been drawn in.)
- Pulmonary oedema
- Fig. 3.10 Septal lines known as Kerley B lines in a patient with mitral stenosis. Note that these oedematous septa are horizontal, non-branching lines that reach the pleura. One such line in the right costophrenic angle is arrowed.
- Fig. 3.11 Alveolar oedema in a patient with acute left ventricular failure following a myocardial infarction. The oedema fluid is concentrated in the more central portion of the lungs leaving a relatively clear zone peripherally. Note that all the lobes are fairly equally involved.
- Heart size and shape
- Echocardiography
- Fig. 3.12 Normal two-dimensional echocardiogram. (a) Parasternal long axis view. (b) Apical four-chamber view. (c) Parasternal short axis view at the level of the papillary muscles. (d) Similar view to (c) but at the level of the mitral valve. The dots indicate the area of the open valve. Ao, aorta; AV, aortic valve; IVS, interventricular septum; LA, left atrium; LV, left ventricle; MV, mitral valve; Pap, papillary muscles; PW, posterior wall of LV; RA, right atrium; RV, right ventricle. Courtesy of Andrew A. McLeod and Mark J. Monaghan.
- Fig. 3.13 Diagram illustrating the three orthogonal imaging planes used to demonstrate the heart with two-dimensional echocardiography. Ao, aorta; LV, left ventricle; PA, pulmonary artery; RA, right atrium; RV, right ventricle.
- Doppler echocardiography
- Fig. 3.14 Aortic valve disease. (a) Colour flow Doppler in a patient with aortic regurgitation. Apical four-chamber view showing turbulent jet (white) of regurgitant blood impinging on the anterior leaflet of the mitral valve to mix with the stream (red) passing from the left atrium (LA) to the left ventricle (LV). Note the change in colour to blue as the stream is directed by the ventricular apex towards the aortic valve. A small portion of right atrial to right ventricular flow is depicted in red. A, aorta; RA, right atrium; RV, right ventricle. (b) Continuous wave Doppler from the apical position in a patient with aortic stenosis and regurgitation showing a high velocity (7 m/s) jet into the aorta (Ao). There is immediate diastolic flow back into the LV, representing aortic regurgitation.
- Fig. 3.15 Atrial septal defect. Colour flow Doppler in the subcostal four-chamber view showing substantial flow (red) passing from the left to right atrium. LA, left atrium; LV, left ventricle; RA, right atrium; RV, right ventricle.
- Myocardial perfusion scintigraphy
- Fig. 3.16 Thallium-201 myocardial perfusion scans. On the exercise scan there is a large area of very reduced uptake in the inferior wall of the left ventricle (LV; arrow), with normal redistribution of the thallium on the rest scan indicating an area of ischaemia. Only the left ventricular wall is demonstrated as there is too little uptake of thallium by the normal right ventricle (RV).
- Positron emission tomography
- Fig. 3.20 CT coronary angiography showing haemodynamically insignificant coronary artery disease. (a) Oblique coronal reconstruction showing the left coronary artery on the posterior surface of the heart. (b) Three-dimensional reconstruction of the aortic root and both coronary arteries.
- Fig. 3.21 Coronary artery disease. (a) Left coronary artery injection showing a moderate stenosis between the arrows in the mid left anterior descending artery. (b) Right coronary artery injection showing tight stenosis (arrow) of the mid right coronary artery.
- Box 3.3 Information available from cardiac gated MRI
- Heart failure
- Fig. 3.17 Congestive cardiac failure. There are large bilateral pleural effusions. The heart is enlarged although it is difficult to measure it precisely because the pleural fluid obscures its borders.
- Ischaemic heart disease
- Fig. 3.18 Left ventricular aneurysm due to ischaemic damage. The three-chamber view, T2-weighted image shows a dilated left ventricle with a thin wall, particularly at the apex (white arrows). There is a hypointense intracavitary thrombus (black arrow) due to marked reduction of apical contraction.
- Fig. 3.19 Myocardial infarction on MRI. T1-weighted inversion recovery image acquired at 15 minutes after injection of gadolinium (late gadolinium enhancement). (a) There is a large area of hyperintensity (due to slow clearance of gadolinium) in the anterior wall and apex (arrows) consistent with scar tissue, suggesting transmural myocardial infarction. Also note an apical thrombus (*). (b) In a different patient, the normal myocardium demonstrates uniform low signal intensity (arrow).
- Hypertensive heart disease and other myocardial diseases
- Fig. 3.22 Hypertrophic obstructive cardiomyopathy (HOCM). Axial T2-weighted MRI demonstrating the four-chamber view. (a) There is an asymmetrical focal hypertrophy of the septum to 2.5 cm (arrow) and a normal lateral ventricular wall (*). LA, left atrium; LV, left ventricle; RV, right ventricle. (b) The anterior cusp of the mitral valve (arrow) contacts the septum during diastole – a diagnostic feature of this condition.
- Fig. 3.23 Subacute myocarditis on MRI. (a) T2-weighted image with fat suppression showing diffuse hyperintensity of the left ventricular wall (arrows) suggesting myocardial oedema, in keeping with myocarditis. (b) Delayed post contrast T1-weighted image showing areas of hyperintensity (arrows) with a patchy subepicardial pattern indicative of myocardial damage.
- Valvular heart disease
- Fig. 3.24 Mitral stenosis on two-dimensional echocardiogram, parasternal long axis view. (a) The mitral valve is markedly thickened and shows calcification. The image is during diastole when the valve should be open, but in this case the orifice is narrowed and opening is impaired. (b) Normal image for comparison. Ao, aorta; IVS, interventricular septum; LA, left atrium; RV, right ventricle. Courtesy of Andrew A. McLeod and Mark J. Managhan.
- Pericardial effusion
- Fig. 3.25 (a) Large pericardial effusion on an apical four-chamber view echocardiogram. LA, left atrium; LV, left ventricle; RA, right atrium; RV, right ventricle. (b) CT scan showing fluid density (stars) in the pericardium.
- Subacute bacterial endocarditis
- Fig. 3.26 Periaortic root abscess. (a) Transoesophageal echocardiogram (TOE) with Doppler showing a nearly 3 cm hyperechoic mass (*) adjacent to the aorta (Ao). Note that the mass is bulging into the left atrium (LA). LV, left ventricle. (b) T2-weighted axial MRI with fat suppression showing hyperintensity of the periaortic tissue in keeping with an abscess (arrow).
- Left atrial myxoma and other intracardiac masses
- Fig. 3.27 Left atrial myxoma. (a) Axial CT image in the arterial phase post contrast medium injection showing a smooth mass (approximately 4.5 cm) in the left atrium (arrow). (b) Repeat scan 5 minutes post contrast injection revealing inhomogenous inner enhancement, which is typical in myxoma (arrow), although may also rarely be seen in thrombi.
- Congenital heart disease
- Breast Imaging
- Mammography
- Fig. 4.1 Mammographic images of breast cancer. (a) Left mediolateral oblique and (b) compressed magnified left craniocaudal views of an irregular spiculated mass (black arrow) with associated pleomorphic microcalcification (white arrow) behind the nipple with associated architectural distortion and nipple retraction.
- Box 4.1 Key mammographic signs of breast cancer
- Fig. 4.2 Mammographic image of a benign breast lesion. (a) Right mediolateral oblique and (b) craniocaudal views of the right breast demonstrating a very well-defined ovoid mass in the upper outer quadrant of the breast (arrow).
- Breast ultrasound
- Fig. 4.3 Ultrasound image of a benign breast lesion. There is a very well-defined hypoechoic ovoid mass typical of a benign fibroadenoma. This is the same patient as in Fig. 4.2.
- Fig. 4.4 Ultrasound of a breast cancer. (a) An irregular spiculated heterogenous mass containing hyperechoic microcalcification (arrow). (b) On Doppler interrogation, there is intense malignant vascularity. This is the same patient as in Fig. 4.1.
- Breast magnetic resonance imaging
- Fig. 4.5 Breast cancer with ductal carcinoma in situ. (a) Mammography demonstrates an irregular malignant mass (black arrow) with some associated microcalcification. (b) Axial contrast-enhanced subtracted MRI reveals the enhancing index mass (short arrow) and an additional unsuspected malignancy posteriorly (long arrow) with intervening linear and nodular enhancement typical of ductal carcinoma in situ (dashed arrow).
- Breast screening
- Fig. 4.6 Early breast cancer detected at screening mammography. (a) Left mediolateral oblique mammogram and (b) compressed craniocaudal view demonstrating a very small impalpable cancer (arrow).
- Fig. 5.1 Normal plain abdominal film. (a) Normal abdomen. The arrows point to the lateral borders of the psoas muscles. The renal outlines are obscured by the overlying colon. (b) Normal extraperitoneal fat stripe. Part of the right flank showing the layer of extraperitoneal fat (arrows), which indicates the position of the peritoneum.
- Intestinal gas pattern
- Dilatation of the bowel
- Fig. 5.2 Small bowel obstruction due to adhesions. (a) The jejunal loops are markedly dilated and show air – fluid levels in the erect film. The jejunum is recognized by the presence of valvulae conniventes. (b) The ‘stack of coins’ appearance is well demonstrated in the supine film. Note the large bowel contains less gas than normal.
- Fig. 5.3 Large bowel obstruction due to carcinoma at the splenic flexure. There is marked dilatation of the large bowel from the caecum to the splenic flexure.
- Table 5.1 Patterns of bowel dilatation in gastrointestinal conditions
- Fig. 5.4 Paralytic ileus. There is considerable dilatation of the whole of the large bowel extending well down into the pelvis. Small bowel dilatation is also seen.
- Fig. 5.5 Volvulus of the caecum. The twisted obstructed caecum and ascending colon now lie on the left side of the abdomen and appear as a large gas shadow. There is also extensive small bowel dilatation from obstruction by the volvulus.
- Fig. 5.6 Toxic dilatation of the large bowel from ulcerative colitis. The dilatation is maximal in the transverse colon. Note the loss of haustra and islands of hypertrophied mucosa. Two of these pseudopolyps are arrowed.
- Pneumoperitoneum
- Fig. 5.7 Free gas in the peritoneal cavity. On this chest radiograph, air can be seen under the domes of both hemidiaphragms. The curved arrow points to the left hemidiaphragm and the arrow head to the wall of the stomach. The two vertical arrows point to the diaphragm and upper border of the liver.
- Gas in an abscess
- Fig. 5.8 Gas in a right subphrenic abscess. There are several collections of gas within the abscess. The largest of these contains a fluid level (arrowheads). The air – fluid level under the left hemidiaphragm is normal. It is in the stomach.
- Gas in the wall of the bowel
- Fig. 5.9 Necrotizing enterocolitis in a neonate. There is intramural gas throughout the colon.
- Gas in the biliary system
- Fig. 5.10 Gas in the biliary tree. The gall bladder (curved arrows) and the duct system (straight arrows) have been outlined with air. The patient had an anastomosis of the common bile duct to the bowel.
- Fig. 5.11 Ascites. Note how the gas in the ascending and descending colon (arrows) is displaced by the fluid away from the side walls of the abdomen.
- Box 5.1 Causes of abdominal calcification
- Fig. 5.12 Calcified phleboliths in the pelvis. The arrow points to one of the phleboliths.
- Fig. 5.13 Calcified mesenteric lymph nodes from old tuberculosis (arrows).
- Fig. 5.14 Calcified abdominal aortic aneurysm (arrows). The aneurysm measured 8 cm in diameter on the lateral view.
- Fig. 5.15 Calcification in a large uterine fibroid.
- Fig. 5.16 Adrenal calcification (arrow).
- Fig. 5.17 Pancreatic calcification.
- Fig. 5.18 Appendolith. The oval calcified shadow (arrowhead) is a faecolith in the appendix. The patient had perforated appendicitis. Note the dilated loops of small bowel in the centre of the abdomen due to peritonitis – the so-called sentinel loops.
- Fig. 5.19 Mass arising out of the pelvis (arrows) displacing bowel to the sides of the abdomen. The mass was a large cystadenocarcinoma of the ovary.
- Imaging techniques: general principles
- Contrast examinations
- Computed tomography
- Ultrasound examinations
- Fig. 6.65 Appendicitis. (a) Longitudinal ultrasound scan demonstrating marked thickening of the wall of the appendix (double head arrows). Fluid is seen within the lumen and surrounding the appendix (white arrows). (b) An appendicolith is seen in the tip of the appendix in a different patient (black arrow). A double-headed arrow again indicates thickening of the appendix wall.
- Magnetic resonance imaging
- Fig. 6.43 Perianal fistula in Crohn’s disease on MRI. (a) Axial MRI using a specialized sequence which is T2-weighted with fat saturation (STIR sequence) demonstrating air and fluid within a cavity that runs in the left intersphincteric space, involving the external sphincter (arrows). (b) Coronal STIR demonstrating air within the fistula as well as bright inflammatory change in the ischiorectal fat (arrow). AC, anal canal.
- Nuclear medicine
- Fig. 6.11 FDG-PET/CT in a patient with oesophageal carcinoma. The PET component of the study demonstrates the primary tumour (T) at the lower oesophagus. In addition, there is a hot spot over the liver (long arrow).
- Basic descriptive terms
- Fig. 6.1 Ulceration. (a) In profile the ulcer is seen as an outward projection (arrow). (b) En face the ulcer appears rounded (arrow).
- Fig. 6.2 Filling defects in the bowel. (a) Intraluminal. (b) Intramural; note the sharp angle (arrow) made with the wall. (c) Extramural; there is a shallow angle (arrow) with the wall of the bowel.
- Fig. 6.3 Stricture. (a) Tapering ends (arrow). (b) Overhanging edges or shouldering (arrow).
- Imaging techniques
- Plain films
- Fig. 6.4 (a) Foreign body in the oesophagus. Lateral view of the neck showing a chicken bone (arrow) lodged in the upper end of the oesophagus. (b) A nasogastric tube has been placed down the right main bronchus (arrow). (c) A nasogastric tube has coiled within an oesophageal pouch (arrows). Note that barium has been used to demonstrate the pouch.
- Barium swallow examination
- Fig. 6.5 Normal oesophagus. (a) Full of barium to show the smooth outline and indentation made by the aortic arch (arrow). (b) Film taken after the main volume of barium has passed, to show the parallel mucosal folds.
- Fig. 6.6 Tertiary contractions (corkscrew oesophagus) giving the oesophagus an undulated appearance.
- Box 6.1 Indications for contrast studies of the oesophagus
- Computed tomograpphy
- Fluorodeoxyglucose positron emission tomography/computed tomography
- Plain films
- Oesophageal abnormalities
- Strictures of the oesophagus
- Oesophageal carcinoma
- Fig. 6.7 Oesophageal carcinoma. There is an irregular stricture with shouldering (arrow) at the upper end.
- Box 6.2 Causes of strictures or narrowing of the oesophagus
- Fig. 6.8 EUS of oesophageal carcinoma. Note the thickening of the oesophageal mucosa (between the white arrows). A normal part of the oesophagus is indicated by the black arrow. E, endoscope.
- Fig. 6.9 Oesophageal cancer on CT. There is thickening and enhancement of the right lateral oesophageal wall (black arrow). In this case, the left wall of the oesophagus is relatively normal (white arrow). A, aorta.
- Fig. 6.10 (a) Extensive oesophageal cancer (black arrow) has eroded into the posterior aspect of the carina (*) forming a fistula. Enlarged lymph nodes are present in the anterior mediastinum (white arrow). (b) A stent has been placed across the fistula (arrows). (c) Barium swallow confirms occlusion of the fistula, with no leakage of barium into the bronchial tree.
- Peptic strictures
- Fig. 6.12 Peptic stricture due to gastro-oesophageal reflux in a patient with a hiatus hernia. There is a short smooth stricture at the oesophagogastric junction with an ulcer crater within the stricture (arrow).
- Achalasia
- Fig. 6.13 Achalasia. The very dilated oesophagus containing food residues shows a smooth narrowing at its lower end.
- Corrosive strictures
- Fig. 6.14 Corrosive stricture.
- Benign tumours
- Other medistinal masses
- Anomalous right subclavian artery
- Fig. 6.15 Anomalous right subclavian artery. There is a localized indentation caused by the anomalous artery as it passes behind the oesophagus (arrow).
- Dilatation of the oesophagus
- Oesophageal carcinoma
- Other abnormalities of the oesophagus
- Fig. 6.16 Oesophageal web. There is a shelf-like indentation (arrow) from the anterior wall of the upper oesophagus.
- Fig. 6.17 Pharyngeal pouch (Zenker’s diverticulum). The pouch lies behind the oesophagus, which is displaced forward.
- Fig. 6.18 Diagram of the various types of oesophageal atresia. The first two types also have an oesophagotracheal fistula distal to the atretic segment and will show air in the stomach.
- Strictures of the oesophagus
- Imaging techniques
- Barium meal examination
- Fig. 6.19 Normal stomach and duodenum on double-contrast barium meal. On this supine view, barium collects in the fundus of the stomach. The body and the antrum of the stomach together with the duodenal cap and loop are coated with barium and distended with gas. Note how the fourth part of the duodenum and duodenojejunal flexure are superimposed on the body of the stomach.
- Fig. 6.20 Duodenal diverticulum arising from the second part of the duodenum (arrowheads).
- Computed tomography
- Fig. 6.21 CT of a normal stomach. The stomach has been distended by oral water contrast and the use of an intravenous smooth muscle relaxant. Some normal rugal folds are still visible (black arrows). Note the gastro-oesophageal junction (white arrow). A, aorta L, liver; S, stomach.
- Box 6.3 Indications for contrast studies of the stomach and duodenum
- Box 6.4 Indications for upper gastrointestinal (GI) endoscopy
- Barium meal examination
- Peptic ulcer
- Fig. 6.22 Benign ulcer. (a) In profile, the ulcer (arrow) projects from the lesser curve of the stomach. (b) En face the ulcer (arrow) is seen as a rounded collection of barium.
- Gastric carcinoma
- Fig. 6.23 Gastric carcinoma on barium study. There are a number of large filling defects in the antrum and body of the stomach.
- Fig. 6.24 Gastric carcinoma on CT. (a) A focal ulcer is seen arising in the antrum (arrows). (b) In a different patient, there is diffuse thickening of the wall of the stomach (white arrows). Several lymph nodes (short black arrows) and a liver metastasis (long black arrow) are also seen. GB, gall bladder; L, liver; P, pancreas.
- Other gastric tumours
- Fig. 6.25 Gastrointestinal stromal tumour on CT. There is a smooth ovoid mass arising from the anterior wall of the stomach (arrow). This causes an indentation of the stomach. L, liver; P, pancreas; St, stomach.
- Fig. 6.26 Duodenal gastrinoma. The duodenum has been distended using a smooth muscle relaxant and oral water. The tiny gastrinoma is seen as a brightly enhancing lesion in the wall of the duodenum (arrow), on the arterial phase of enhancement. A, aorta; D, duodenal lumen; K, kidney.
- Gastric polyps
- Fig. 6.27 CT of a bezoar. The stomach is distended by a large mass of hair mixed with oral contrast (white arrows). The antrum is also distended by the ingested material (black arrow).
- Lymphoma
- Fig. 6.28 Gastric lymphoma in the antrum, demonstrated on CT (white arrows). Lymphadenopathy surrounds the inferior vena cava (black arrow). St, stomach; Sp, spleen.
- Gastric outlet obstruction
- Fig. 6.29 Pyloric stenosis. Ultrasound scan in a neonate showing a thickened, elongated pyloric canal.
- Box 6.5 Causes of gastric outlet obstruction
- Hiatus hernia
- Fig. 6.30 Hiatus hernia. (a) Sliding: a portion of the stomach and the gastro-oesophageal junction are situated above the diaphragm. (b) Rolling or para-oesophageal: the gastro-oesophageal junction is below the diaphragm.
- Fig. 6.31 Sliding hiatus hernia. The fundus of the stomach and the gastro-oesophageal junction (arrow) have herniated through the oesophageal hiatus and lie above the diaphragm (dotted line).
- Fig. 6.32 Hiatus hernia. (a) Chest x-ray demonstrating a rounded mass (arrow) with an air – fluid level projected behind the heart shadow. (b) CT in the same patient demonstrating the fundus of the stomach extending up into the posterior mediastinum (arrow). A, aorta.
- Fig. 6.33 A capsule endoscope within a loop of small bowel (arrow). A nasogastric tube is also present, projected over the left upper quadrant.
- Imaging techniques
- Fig. 6.34 (a) Normal barium follow-through. The small intestine, ascending and transverse colon are filled with barium. The jejunum in the left side of the abdomen has a much more marked mucosal fold pattern than the ileum, which is lying in the pelvis. When a peristaltic wave contracts the bowel, the mucosal folds lie longitudinally (arrows). Note the way of measuring the diameter of the bowel. In the pelvis the loops overlap and details of the bowel become hidden. (b) Normal terminal ileum.
- Fig. 6.35 Normal enteroclysis (small bowel enema). This technique gives good mucosal detail. The arrow points to the terminal ileum. Note that a tube has been passed through the stomach into the jejunum.
- Normal appearances of the small bowel
- Box 6.6 Indications for small bowel follow-through
- Fig. 6.36 Normal CT of the small bowel. The small bowel contains Gastrografin contrast medium. Note the feathery appearance of the jejunal loops (arrow).
- Imaging signs of disease of the small intestine
- Dilatation
- Fig. 6.37 Dilatation from small bowel obstruction. The diameter of the bowel is greatly increased. The feathery mucosal pattern is lost and the folds appear as thin lines traversing the bowel, known as valvulae conniventes (arrows).
- Mucosal abnormality
- Fig. 6.38 Mucosal abnormality with infiltration of the bowel, in this case from oedema. The mucosal folds become thickened (some are arrowed).
- Narrowing
- Fig. 6.39 Narrowing. (a) There is a long stricture (arrows) in the ileum due to Crohn’s disease and an abnormal mucosal pattern. There is also separation of the abnormal segment from other loops of the bowel. (b) CT in the same patient demonstrating marked thickening of the abnormal loop of small bowel, with a narrowed lumen (white arrows). Several dilated loops of small bowel are also seen (black arrows), due to some obstruction at the level of the stricture.
- Ulceration
- Fig. 6.40 Ulceration. Abnormal loops of bowel in Crohn’s disease showing the ulcers as outward projections (arrows).
- Dilatation
- Crohn’s disease
- Fig. 6.41 MRI of Crohn’s disease. (a) Coronal T2 and (b) coronal T1 post contrast images demonstrating mucosal thickening and enhancement involving the terminal ileum (arrows), characteristic of Crohn’s disease.
- Fig. 6.42 CT of a fistula (white arrows) between the ileum and the sigmoid colon in a patient with Crohn’s disease. Note the thickened and inflamed loop of ileum (black arrow).
- Small bowel ischaemia
- Fig. 6.44 Axial CT showing a thrombus in the superior mesenteric artery (arrow).
- Tuberculosis
- Lymphoma
- Fig. 6.45 Lymphoma. Lymphomatous infiltration has occurred in the lower loops of the bowel causing thickening of the mucosal folds (small arrows) and discrete filling defects due to tumour nodules (curved arrows).
- Fig. 6.46 Lymphoma. CT with the bowel opacified by contrast agent. The wall of all the bowel loops is considerably thickened. The arrows point to a portion of bowel which is particularly involved by lymphoma.
- Malabsorption
- Fig. 6.47 Malabsorption. The bowel is dilated and the mucosal folds thickened. In the lower loops the barium appears less dense due to it becoming diluted. No specific cause for the malabsorption can be detected, which in this case was due to gluten enteropathy.
- Fig. 6.48 Diverticulosis. A number of diverticula of varying size can be seen arising from the small bowel (some are arrowed).
- Acute small bowel obstruction
- Fig. 6.49 CT of small bowel obstruction in a patient with recurrent ovarian cancer. There is an abrupt change in calibre of the dilated small bowel lumen (arrow) where a mass (M) is infiltrating the bowel wall.
- Malrotation
- Worm infestation
- Fig. 6.50 Worm infestation. Several long, tubular filling defects (arrows) can be seen due to roundworms (Ascaris) in the small bowel.
- Imaging techniques
- Colonoscopy
- Barium enema
- Computed tomography pneumocolon
- Fig. 6.75 Colon carcinoma shown by CT pneumocolon. (a) Oblique axial section showing a stricture with classic shouldered edges (arrows). (b) Virtual colonoscopy demonstrating the irregularly shaped tumour (arrows).
- Magnetic resonance imaging
- Nuclear medicine studies
- Normal appearance of the colon
- Fig. 6.51 Normal double-contrast barium enema.
- Imaging signs of disease of the large intestine
- Narrowing of the lumen
- Box 6.7 Causes of narrowing of the colonic lumen
- Fig. 6.52 Stricture. (a) Barium enema and (b) coronal CT showing a short, circumferential narrowing in the sigmoid colon (arrows) from a carcinoma.
- Dilatation
- Filling defects
- Fig. 6.53 Filling defects. Lumps of faeces have caused smooth filling defects surrounded by barium. However, in the sigmoid colon there is a large filling defect with ill-defined edges (arrow); this is a carcinoma. A clean colon is essential for a satisfactory barium enema.
- Diverticula and muscle hypertrophy
- Fig. 6.54 (a) Muscle hypertrophy and diverticula. Muscle hypertrophy gives the sigmoid colon a serrated appearance. Two small diverticula are arrowed. (b) Axial T2-weighted MRI in a different patient demonstrating multiple air-filled diverticula in the sigmoid colon (black arrow). Note the normal low signal intensity of the cervix (white arrow).
- Ulceration
- Fig. 6.55 Ulceration. (a) Single contrast. (b) Double contrast. In this case of ulcerative colitis, the ulceration causes the normally smooth outline of the colon to be irregular.
- Narrowing of the lumen
- Inflammatory bowel disease
- Ulcerative colitis
- Fig. 6.56 Ulcerative colitis. With longstanding disease, the haustra are lost and the colon becomes narrowed and shortened, coming to resemble a rigid tube. Reflux into the ileum through an incompetent ileocaecal valve has occurred.
- Fig. 6.57 MRI of chronic ulcerative colitis. (a) Axial T2-weighted image demonstrating a complete loss of haustra in the sigmoid colon (arrow). (b) Axial T1-weighted image demonstrating increased submucosal fibro-fatty changes in the rectum, which is of high signal intensity on T1 (arrow).
- Fig. 6.58 Toxic megacolon demonstrated on CT. The transverse and descending colon are thick-walled and inflamed with enhancement of the mucosa and marked dilatation of the lumen.
- Crohn’s disease
- Fig. 6.59 Crohn’s disease. The mucosal pattern has a ‘cobblestone’ appearance due to criss-crossing fine ulceration.
- Fig. 6.60 Crohn’s disease. Very deep ulcers are present; two examples of an ulcer tracking in the submucosa are arrowed.
- Fig. 6.61 Strictures in Crohn’s disease. A long stricture is present in the transverse colon (between the curved arrows) and a shorter one in the sigmoid colon (between the small arrows). In this case, the outline of the strictures is irregular due to ulceration. These two abnormal segments with normal intervening bowel are an example of ‘skip lesions’ – an important diagnostic feature of Crohn’s disease.
- Fig. 6.62 Rectovaginal fistula in Crohn’s disease. During the barium enema, filling of the vagina with barium occurred. Note the ulceration in the rectum.
- Ulcerative colitis
- Fig. 6.63 Diverticular disease. Numerous diverticula are seen as out-pouchings from the sigmoid colon (arrow). There is marked stranding of the surrounding fat planes. In this case there is no associated abscess.
- Fig. 6.64 Diverticular disease. A stricture is present (arrow). Although there is recognizable diverticular disease at both ends of the stricture, it is impossible to definitely exclude a carcinoma.
- Fig. 6.66 Appendix abscess. (a) CT showing a mass (arrows) in the right iliac fossa. (b) The abscess was drained under CT guidance.
- Fig. 6.67 Ischaemic colitis, in three different patients. (a) Coronal CT showing a stricture (arrow) and proximal bowel dilatation (*) which developed following thrombus in the superior mesenteric artery a few months previously (see Fig. 6.44). (b) Barium enema demonstrating mucosal haemorrhage and oedema that have caused indentations resembling thumb prints in the transverse colon. (c) A long smooth stricture involving the splenic flexure with sacculations arising from the colon (arrows).
- Fig. 6.68 Pneumatosis coli. Part of the colon showing numerous translucencies in the colon wall owing to many gas-filled cysts.
- Fig. 6.69 Volvulus. A smooth narrowing is seen in the sigmoid colon where the colon has twisted (arrow). Note the dilated colon proximal to this.
- Fig. 6.70 Intussusception. Ultrasound of the upper abdomen showing the intussusception as a mass (arrows).
- Fig. 6.71 Intussusception. (a) Film taken during reduction of the intussusception with air insufflated per rectum showing a filling defect in the transverse colon (arrow) owing to ileum invaginated into the colon. (b) Later film showing that the intussusception has been reduced, with air filling the caecum and entering the small bowel.
- Fig. 6.72 Intussusception due to a tumour on CT. (a) Axial and (b) coronal reformat demonstrating a sausage-shaped mass in the right iliac fossa (arrows). Mesenteric fat and vessels are seen in the centre of the mass.
- Polyps
- Fig. 6.73 Polyps. (a) Pedunculated polyp (arrow) outlined by barium in the sigmoid colon. (b) Sessile polyp (arrow) in the rectum. (c) CT pneumocolon of a sessile polyp (arrow) in large bowel.
- Carcinoma
- Fig. 6.74 Colon carcinoma. (a) Standard axial CT acquired on thin sections showing a tumour (arrows) in the transverse colon. (b) Coronal reformat of the same tumour (arrows).
- Fig. 6.76 MRI of rectal carcinoma. (a) Sagittal T2-weighted image demonstrating a polypoid growth (arrow) arising from the anterior wall of the rectum. Note the benign hyperplasia of the prostate (P) and a slightly trabeculated bladder (B). (b) Axial image of the same tumour (white arrow). Note the mesorectal fascia (black arrows) that encases the mesorectal fat and the rectum.
- Fig. 6.77 MRI of advanced rectal carcinoma. The tumour (arrows) has completely invaded the perirectal fat and fascia and there is infiltration of the seminal vesicles (SV).
- Staging colorectal carcinoma.
- Fig. 6.78 Locally advanced cancer of the transverse colon (black arrows) on a CT coronal reformat. Multiple peritoneal metastases (white arrow) are seen beneath the diaphragm and there is ascites (A) consistent with metastatic disease.
- Fig. 6.79 Hirschsprung’s disease. Note the transition between the normal calibre aganglionic rectum and the dilated sigmoid colon.
- Imaging investigation of the acute abdomen
- Box 6.8 Common causes of acute abdomen
- Plain films
- Barium or Gastrografin follow-through
- Ultrasound
- Computed tomography
- Fig. 6.80 Pseudomembranous colitis secondary to Clostridium difficile infection. There is gross thickening of the colonic wall, thickened enhancing mucosa (arrows) and inflammatory changes and free fluid (F) in the surrounding tissues.
- Fig. 6.81 Acute lower GI bleed. (a) CT arteriogram demonstrating arterial blush at the site of bleeding in the transverse colon (arrow). (b) Digital subtraction arteriogram in the same patient showing active extravasation (arrow) from a branch of the inferior mesenteric artery, which was subsequently embolized.
- Fig. 6.82 Meckel’s diverticulum. 99m Tc-pertechnetate scan showing an isolated area of uptake in the ectopic gastric mucosa in a Meckel’s diverticulum (arrow). Normal uptake of radionuclide is seen in the stomach.
- LIVER
- Imaging techniques
- Ultrasound
- Fig. 7.1 Ultrasound of normal liver. Longitudinal scan showing a uniform echo pattern interspersed with bright echoes of portal triads and echo-free areas of hepatic and portal veins. D, diaphragm; K, right kidney.
- Fig. 7.2 Ultrasound of normal liver. Transverse scan across the porta hepatis. Ao, aorta; IVC, inferior vena cava; PV, portal vein.
- Fig. 7.3 Ultrasound of normal liver. Transverse scan through the superior portion of the liver showing the right (R), middle (M) and left (L) hepatic veins draining into the inferior vena cava (IVC) as it penetrates the diaphragm (D).
- Fig. 7.4 Ultrasound of a benign cyst. Note the imperceptible wall and absence echoes within the cyst. There is also posterior acoustic enhancement (increased echogenicity of structures deep to the cyst) secondary to enhanced transmission of the ultrasound waves through the water density of the cyst. V, hepatic veins.
- Fig. 7.5 Ultrasound of a solid mass. Longitudinal scan showing an echogenic mass (indicated by cursors), which proved to be a metastasis. D, diaphragm; IVC, inferior vena cava.
- Fig. 7.6 Ultrasound of complex mass. Longitudinal scan of an abscess showing a spherical mass (arrows) with areas of echogenicity both greater and less than normal liver.
- Computed tomography
- Fig. 7.7 CT scan of normal liver through the porta hepatis (enhanced scan). Ao, aorta; C, colon; IVC, inferior vena cava; K, kidney; P, portal vein; Sp, spleen; St, stomach. The single arrow indicates a fissure for the falciform ligament, and the double arrows a fissure for the gall bladder, which divides the liver into the right and left lobes.
- Fig. 7.8 The liver is divided anatomically into eight segments, each of which has its own independent vascular supply and biliary drainage.
- Fig. 7.9 CT scan of normal liver showing unopacified veins (arrows), which should not be confused with metastases.
- Magnetic resonance imaging
- Fig. 7.10 Normal T2-weighted MRI scan of the upper abdomen. The liver parenchyma (L) shows intermediate signal intensity. The cerebral spinal fluid has high signal intensity (arrow). A, aorta; C, splenic flexure of colon; K, kidney; P, pancreas; Sp, spleen; St, stomach.
- Ultrasound
- Imaging techniques
- Liver masses
- Box 7.1 Types of liver masses
- Malignant liver neoplasms
- Fig. 7.11 Ultrasound of liver metastases. (a) Multiple hyperechoic metastases scattered throughout the liver. (b) Multiple metastases appearing as well-defined, round, hypoechoic lesions scattered throughout the liver. (c) The cursors indicate a metastasis showing reduced echogenicity, but with an echogenic centre known as a target lesion.
- Fig. 7.12 CT scan of liver metastases. (a) There are a large number of low density lesions in both lobes of the liver, which show enhancement around their edges. The patient had carcinoma of the bronchus. (b) Vascular metastases (arrow) due to a carcinoid tumour (T) appearing as areas of high density on this arterial phase image.
- Fig. 7.13 Liver metastasis on MRI. (a) T1-weighted MRI scan showing a solitary low signal intensity focus in the liver (arrow). (b) T2-weighted MRI (with fat saturation) showing the same metastasis. This is of higher signal intensity than the normal liver parenchyma; however, the signal intensity is not as bright as a haemangioma or cyst. GB, gall bladder; K, kidney.
- Fig. 7.14 CT scan of hepatoma showing a large mass of variable density (arrows).
- Benign liver masses
- Liver cysts
- Fig. 7.15 CT scan of liver cysts. (a) Simple cysts. CT shows several well-defined, low attenuation lesions of near water density. Note their density is equivalent to the bile in the gall bladder (arrowed). (b) Complex cyst. CT scan showing a multilocular hydatid cyst with calcification in its wall.
- Haemangiomas of the liver
- Fig. 7.16 Haemangioma (incidental finding). (a) Ultrasound scan showing an echogenic mass in the right lobe of the liver (arrow). IVC, inferior vena cava. (b) CT scan, in another patient, after intravenous contrast enhancement showing a low density lesion in the right lobe of the liver (arrow) with peripheral nodular enhancement, characteristic of a haemangioma.
- Fig. 7.17 MRI of a haemangioma. (a) Low signal intensity focus (arrow) on a coronal T1-weighted image. (b) High signal intensity focus (arrow) on a coronal T2-weighted image. L, right lung base; Sp, spleen.
- Adenoma and focal nodular hyperplasia
- Fig. 7.18 MRI of focal nodular hyperplasia. (a) Axial T2-weighted image demonstrating a mass in the right lobe of the liver that is isointense to normal liver with a hyperintense central scar (arrow). S, stomach. (b) An axial TI-weighted arterial phase image, post contrast, demonstrating avid enhancement of the mass with sparing of the central scar. These features are characteristic of focal nodular hyperplasia.
- Liver cysts
- Fig. 7.19 Liver abscess. (a) Ultrasound scan showing an area of mixed echogenicity in the liver. (b) CT in another patient showing multifocal areas of low attenuation. Compared to liver cysts (see Fig. 7.15a), they are not nearly as well circumscribed.
- Fig. 7.20 Varices on CT due to portal hypertension. There is marked enhancement of multiple serpinginous vessels in the upper abdomen (arrows), extending into the splenic hilum. There is splenomegaly and ascites. S, spleen.
- Fig. 7.21 Liver trauma. CT scan showing laceration in the right lobe of the liver (arrows). A nasogastric tube is present in the stomach.
- Fig. 7.22 Fatty degeneration of the liver shown by CT as a large focal area of reduced attenuation in the right lobe of the liver (arrows).
- Imaging techniques
- Ultrasound
- Fig. 7.23 Ultrasound of normal gall bladder. Note the thin wall and absence of echoes from within the gall bladder. GB, gall bladder; IVC, inferior vena cava; PV, portal vein.
- Fig. 7.24 Normal common bile duct. Longitudinal ultrasound scan showing the common bile duct, situated between the arrows, lying anterior to the portal vein. The common bile duct measures 4 mm in diameter (crosses). D, diaphragm; IVC, inferior vena cava; PV, portal vein.
- Magnetic resonance cholangiopancreatography
- Fig. 7.25 MRCP. A stone is present in the common bile duct (arrow) with dilatation of the ducts above it. A normal pancreatic duct has also been demonstrated (curved arrows).
- Endoscopic retrograde cholangiopancreatography
- Fig. 7.26 ERCP.(a) A normal biliary system has been shown by injecting contrast through a catheter passed from the endoscope into the common bile duct. The pancreatic duct has also been filled. (b) A dilated ductal system with numerous large calculi in the hepatic and common bile ducts. (c) A stricture in the common bile duct from a cholangiocarcinoma is causing marked dilatation of the biliary system above it.
- Percutaneous transhepatic cholangiogram
- Hepatobiliary radionuclide scanning
- Fig. 7.27 Hepatobiliary scan. (a) Normal iminodiacetic acid (IDA) scan. There is obvious filling of the gall bladder (GB). Activity is also present in the duodenum and small bowel. (b) Cystic duct obstruction. The IDA scan in this patient with acute right upper quadrant pain shows the duct system but no filling of the gall bladder. CBD, common bile duct; D, duodenum; SB, small bowel.
- Ultrasound
- Fig. 7.28 Radio-opaque gall stones. Plain film showing multifaceted stones with lucent centres.
- Fig. 7.29 Ultrasound of a gall stone showing a stone (S) in the gall bladder. The arrows point to the acoustic shadow behind the stone.
- Fig. 7.30 Endoscopic ultrasound showing a small polyp in the gall bladder with no acoustic shadow (arrow).
- Cholecystitis
- Fig. 7.31 Acute cholecystitis. (a) Ultrasound showing a thick, oedematous gall bladder wall indicated by the thin arrows. There is also evidence of fluid adjacent to the gall bladder indicative of acute inflammation (thick arrow). (b) CT scan of acute cholecystitis showing a thick-walled gall bladder with adjacent oedema and inflammatory change as evidenced by a surrounding low attenuation rim (thin arrow) and lack of clarity (stranding) in the adjacent fat (thick arrow).
- Box 7.2 Major causes of biliary obstruction
- Fig. 7.32 Dilated biliary ducts. (a) Longitudinal ultrasound scan showing a dilated common bile duct (CBD) measuring 11 mm in diameter lying in front of the portal vein (PV). Normally the duct is much smaller than the accompanying vein. A dilated intrahepatic duct is arrowed. (b) CT scan showing dilated intrahepatic ducts (arrows) in the liver.
- Fig. 7.33 Stones in the common bile duct (CBD). The common bile duct is dilated, measuring 2 cm in diameter, and a large stone (arrow) is seen in its lower portion. PV, section through the portal vein.
- Fig. 7.34 Endoscopic ultrasound showing a mass in the pancreas (arrows) that involves the portal vein (PV). E, endoscope.
- Fig. 7.35 Endoscopic retrograde pancreatography. The pancreatic duct has been cannulated from the endoscope in the duodenum and contrast injected to demonstrate a normal duct system.
- Fig. 7.36 CT scan of normal pancreas. Note that several sections may be needed to display the pancreas. (a) The head of the pancreas (white arrow) nestling between the second part of the duodenum (D) and the superior mesenteric vessels (SMA and SMV). The uncinate process lies anterior to the inferior vena cava (black arrow). (b) CT scan taken 3 cm higher, showing the body and part of the tail (white arrows). Note the splenic vein (black arrow), which lies posterior to the body of the pancreas.
- Fig. 7.37 Ultrasound of normal pancreas (transverse scan). Ao, aorta; CBD, common bile duct; GB, gall bladder; IVC, inferior vena cava; PV, portal vein; SMA, superior mesenteric artery; SV, splenic vein.
- Pancreatic masses
- Box 7.3 Major causes of pancreatic masses
- Fig. 7.38 Carcinoma of the pancreas. (a) CT scan showing a focal mass in the head of the pancreas (white arrow), which involves the portal/mesenteric vein confluence (arrow head) and may preclude curative surgery (compare with the endoscopic ultrasound image, Fig. 7.34, performed in the same patient). Note the dilated intrahepatic bile ducts (black arrows) and distended gall bladder (GB). (b) Transverse ultrasound scan showing a large mass in the body of the pancreas (arrows). Ao, aorta; IVC, inferior vena cava; Sp, spine; Spl V, splenic vein.
- Fig. 7.39 Insulinoma. (a) Axial T2-weighted MRI demonstrating a 1.5 cm insulinoma in the uncinate process of the pancreas (arrow). (b) Selective superior mesenteric angiogram in another patient showing the tumour as a vascular blush (arrows). Ao, aorta; D, duodenum; IVC, inferior vena cava; SMA, superior mesenteric artery.
- Acute pancreatitis
- Fig. 7.40 Acute pancreatitis. (a) CT scan showing diffuse enlargement of the pancreas with ill-defined edges. (b) CT scan showing considerable inflammation around the pancreas (P). (c) Transverse ultrasound scan showing a swollen pancreas (P) with some fluid around the pancreas (arrows).
- Fig. 7.41 Pancreatic pseudocyst. (a) CT scan showing a large cyst arising within the pancreas (arrows). (b) Transverse ultrasound scan. The arrows indicate a pseudocyst arising from the body of the pancreas (P). Same patient as Fig. 7.40c, 6 weeks later.
- Chronic pancreatitis
- Fig. 7.42 Chronic pancreatitis. (a) CT scan showing numerous small areas of calcification within the pancreas (arrows). (b) MRCP showing a normal biliary duct system but irregular dilatation of the pancreatic duct (arrows).
- Pancreatic trauma
- Fig. 7.43 CT scan of a hydatid cyst (C) in the spleen with calcification in its walls.
- Fig. 7.44 Lymphoma. Ultrasound showing an enlarged spleen with several hypoechoic areas within it; some of these are arrowed.
- Fig. 7.45 Splenic infarction. CT with contrast demonstrating a wedge-shaped, non-enhancing segment of spleen (arrow) consistent with infarction.
- Splenic trauma
- Fig. 7.46 Ruptured spleen on CT. The spleen is shattered with low density blood (arrows) adjacent to the fragments. Sp, spleen; St, stomach.
- Imaging techniques
- Ultrasound
- Normal renal ultrasound
- Fig. 8.1 Normal ultrasound of the right kidney.
- Table 8.1 Conditions associated with small kidneys
- Table 8.2 Conditions associated with enlarged kidneys
- Fig. 8.2 Normal ultrasound of the full bladder (B). Note the smooth thin bladder wall. The vagina lies posteriorly (arrow).
- Normal renal ultrasound
- Ultrasound
- Urography
- Box 8.1 Main indications for urography
- Contrast medium and its excretion
- Plain film intravenous urogram
- Identify all calcifications.
- Fig. 8.3 (a) A rounded calcification is seen overlying the left kidney in the anteroposterior plain film. (b) Post contrast film in the same patient. As the contrast medium and the calculus have the same radiographic density, the calculus is hidden by the contrast medium.
- Look at the other structures on the film.
- Identify all calcifications.
- Films taken after injection of contrast medium
- Kidneys
- Fig. 8.4 Normal IVU, full-length 15-minute film. Note that the bladder is well opacified. The whole of the right ureter and part of the left ureter are seen. Often, only a portion of the ureter is visualized owing to peristalsis emptying certain sections. The bladder outline is reasonably smooth. The roof of the bladder shows a shallow indentation from the uterus.
- Fig. 8.5 (a) The distinction between fetal lobulation and renal infarction. With fetal lobulation, indentations in the renal outline are shallow and correspond to the lobules of the kidney, i.e. the indentations are between calices. With renal infarction, the maximal indentation is opposite a calix and there is usually extensive loss of renal parenchyma. (b) Scars in chronic pyelonephritis (drawing of Fig. 8.7b). The reductions in renal parenchymal width are opposite calices, and these calices are dilated. The overall kidney size is reduced, as is usual. Scars in tuberculosis have much the same appearance but are usually associated with other signs of tuberculosis.
- Fig. 8.6 The ‘splenic hump’. (a) A bulge is present on the lateral aspect of the left kidney (arrow) but there is no displacement of the calices. This splenic hump is a normal variant. (b) Coronal MRI (with gadolinium) of a left splenic hump (arrows), in which normal corticomedullary anatomy is demonstrated.
- Calices
- Fig. 8.7 Calices. (a) Normal calices. Each calix is cup-shaped. (b) Many of the calices are clubbed. There is scarring of the parenchyma of the upper half of the kidney indicating that the diagnosis is chronic pyelonephritis. (c) All the calices are dilated, the dilatation of the collecting system extending down to the point of obstruction (arrow), in this case owing to a malignant retroperitoneal lymph node.
- Box 8.2 Causes of dilated calices
- Renal pelvis and ureters
- Fig. 8.49 Bifid collecting system. There is a bifid collecting system on the left with the two ureters joining at the level of the transverse process of L5. Note that the left kidney is larger than the right.
- Bladder
- Kidneys
- Computed tomography urography
- Fig. 8.9 (a) CT section through an opacified bladder in a male patient showing that the bladder wall is too thin to be seen. Note the layering of contrast medium. (b) Section through a bladder without contrast opacification. The bladder wall can be identified as a thin line.
- Fig. 8.10 CT reformat. This is the same patient as in Fig. 8.8a–c. The ureter (arrow) has been reformatted in the coronal plane. A, aorta; B, bladder; I, inferior vena cava; K, kidney.
- Non-contrast ‘CT KUB’
- Fig. 8.22 Non-contrast-enhanced CT reformatted in the coronal plane (a) and sagittal plane (b), demonstrating a hydronephrotic right kidney (RK) and two stones in the dilated right ureter (long arrows). The patient also has kidney stones in the left pelvicaliceal system (short arrows). B, bladder.
- Computed tomography after injection of contrast medium
- Corticomedullary phase.
- Fig. 8.8 Normal CT of kidneys and bladder, with (a–c) showing the same level through the renal hilum. (a) Before the intravenous contrast has been given. Note the calcification in the wall of the aorta (arrow). A, aorta; I, inferior vena cava; K, kidney; Sp, spine. (b) Forty seconds after intravenous contrast infusion, demonstrating the corticomedullary phase, with marked enhancement of the renal cortex. (c) Ten minutes following the contrast infusion, demonstrating homogeneous opacification of the parenchyma and dense opacification of the pelvicaliceal system (arrows). (d) Section through the pelvis showing the ureters (arrows) ten minutes after contrast has been given.
- Nephrographic phase.
- Urographic phase.
- Corticomedullary phase.
- Normal magnetic resonance imaging
- Fig. 8.11 MRI of the kidneys. (a) T1-weighted and (b) T2-weighted images in the axial plane at the level of the renal hila. Note the simple cyst (C) in the left kidney, which returns a low signal on T1-and a high signal on T2-weighted images. (c) Coronal image of the kidneys, in a different patient, following intravenous gadolinium infusion. (d) Normal bladder (B) on a T2-weighted image. The bladder wall is thin and smooth. A, aorta; Cx, cervix; I, inferior vena cava; K, kidney; L, liver; R, rectum; RV, renal vein; Spl, spleen.
- Fig. 8.12 T2-weighted MRI showing a dilated ureter (arrow) due to obstruction by a pelvic mass (M).
- Fig. 8.13 Magnetic resonance angiogram of normal renal arteries, displayed coronally (arrows). There are two renal arteries supplying the right kidney (RK) and one supplying the left kidney (LK). A, aorta.
- Fig. 8.43 Reflux nephropathy (chronic pyelonephritis). (a) IVU showing a severely shrunken kidney with multiple scars and clubbed calices. (b) DMSA scan (posterior view) showing a shrunken left kidney with a focal scar in the upper pole (arrow).
- Fig. 8.14 Indirect voiding cystogram (posterior view) with tracer instilled into the bladder. Voiding is recorded on the gamma camera, starting at image 5. There is immediate reflux into the left ureter (arrow). The bladder is virtually empty on the final image, 7.
- Renogram
- Fig. 8.15 99mTc DTPA renogram, serial images. (a) Vascular phase. (b) Filtration phase. (c) Excretion phase. (d) The renogram curve.
- Retrograde and antegrade pyelography
- Voiding cystourethrogram (micturating cystogram) and videourodynamics
- Fig. 8.62 Posterior urethral valves in a 6-year-old boy. On this micturating (voiding) cystogram, the site of the valves is arrowed. The presence of the valves is recognized by dilatation of the posterior urethra. Note the irregular outline of the thick-walled bladder due to chronic obstruction.
- Urethrography
- Fig. 8.61 Urethral stricture. An ascending urethrogram showing a stricture in the penile urethra (arrow). The patient had gonorrhoea.
- Renal arteriography
- Fig. 8.16 Normal selective right renal arteriogram. Note that not only are the arteries well shown but there is also an excellent nephrogram. The renal pelvis and ureter are opacified because of a previous injection of contrast.
- Urinary calculi
- Fig. 8.17 (a) IVU control film. Renal stones are not visible on the right and are very poorly visualized on the left. (b) IVU following intravenous contrast. Filling defects are seen in the right lower calix and pelvis and in the left upper pole calices (arrows). (c, d) CT of the kidneys in the same patient with no contrast medium, reformatted in the coronal plane, demonstrating the renal stones in both the right (c) and left (d) kidneys (arrows).
- Fig. 8.18 Plain film showing a calcified staghorn calculus in each kidney.
- Fig. 8.19 Ultrasound of stones in the right kidney. The stones (vertical arrows) appear as bright echoes. Note the acoustic shadows behind the stones (horizontal arrows).
- Fig. 8.20 Ultrasound of the bladder (B), demonstrating a stone lodged at the left vesicoureteric junction (arrow). In this case, no acoustic shadow was seen.
- Fig. 8.21 Non-contrast enhanced CT in a patient with crossed fused ectopia, a renal anatomical variant (K). Multiple stones were demonstrated (arrows), allowing accurate planning of his lithotripsy treatment.
- Nephrocalcinosis
- Fig. 8.23 Nephrocalcinosis. (a) On plain film, there are numerous calcifications in the pyramids of both kidneys (the left kidney is not illustrated). (b) In a different patient, bilateral renal parenchymal calcifications are demonstrated on CT KUB. There is also one calculus lying within the right renal pelvis (arrow).
- Urinary tract obstruction
- Ultrasound
- Fig. 8.24 Dilatation of the pelvicaliceal system. (a) Longitudinal ultrasound scan of the right kidney showing spreading of the central echo complex of the dilated collecting system (arrows). (b) Here the dilatation of the calices is greater (arrows).
- Intravenous urogram
- Fig. 8.25 Acute ureteric obstruction from a stone in the lower end of the left ureter. (a) A film taken 30 minutes after the injection of contrast medium. There is obvious delay in the appearance of the pyelogram on the left. The left kidney shows a very dense nephrogram which is characteristic of acute ureteric obstruction. (b) A film taken 23 hours later shows opacification of the obstructed collecting system down to the obstructing calculus (arrowhead).
- Computed tomography
- Fig. 8.26 (a) CT at the corticomedullary phase of enhancement. There is obstruction of the right kidney with dilatation of the pelvicaliceal system, reduced cortical enhancement and some loss of cortical thickness, suggesting that the obstruction may be longstanding. (b) CT at the delayed phase of enhancement. Intravenous contrast is seen in the left renal pelvis but not in the obstructed right renal pelvis. (c) CT through the dilated right ureter (U), in the same patient as (a) and (b). Note the normal left ureter (long arrow). P, renal pelvis.
- Causes of obstruction to the ureters and pelvicaliceal systems
- Causes within the lumen of the urinary tract
- Fig. 8.44 Papillary necrosis showing dilated calices from loss of the papillae. Some of the papillae have sloughed and appear as filling defects within the calices (lower arrow). The upper arrow points to a contrast-filled cavity within a papilla.
- Fig. 8.38 Filling defect due to blood clot in the pelvis and upper ureter (arrow).
- Causes arising in the wall of the collecting system
- Fig. 8.39 Transitional cell carcinoma. (a) Ultrasound demonstrating a polypoid mass arising at the vesicoureteric junction in the bladder (B), extending up the ureter (arrow). (b) CT in the same patient demonstrating thickening and enhancement of the left ureter (arrow).
- Congenital intrinsic pelviureteric junction obstruction
- Fig. 8.27 Intrinsic PUJ obstruction. The pelvicaliceal system is considerably dilated (*). There is an abrupt change in calibre at the level of the PUJ (arrow) and the ureter from the PUJ onward is normal in calibre.
- Fig. 8.28 (a) Diuretic renogram comparing PUJ obstruction (dashed line) with a ‘baggy’ but otherwise normal renal pelvis (continuous line). Frusemide was given at 10 minutes and in the case of the ‘baggy’ pelvis resulted in rapid washout of radioactivity from the kidney. (b) The post diuretic renogram image demonstrates washout of tracer on the unobstructed side and accumulation of tracer in the dilated renal pelvis on the obstructed side (arrow).
- Extrinsic causes of obstruction
- Tumours.
- Retroperitoneal fibrosis.
- Fig. 8.29 Retroperitoneal fibrosis. (a) CT scan demonstrating a cuff of fibrous tissue surrounding the aorta (arrow). The retroperitoneal fibrosis extended down to the level of aortic bifurcation. (b) In a different patient, there is mild hydronephrosis on the right. Both kidneys are surrounded by dense fibrosis, infiltrating the perinephric fat (arrows). (c) The fibrosis extended down the aorta to the pelvis.
- Causes within the lumen of the urinary tract
- Ultrasound
- Ultrasound
- Fig. 8.30 Ultrasound in renal masses. (a) Simple cyst (C) showing sharp walls and no echoes arising within the cyst. Note the acoustic enhancement behind the cyst. (b) Tumour showing echoes within a solid mass (M). (c) Complex cystic mass which could be due to cystic renal cell carcinoma. The short arrow points to the irregular solid part of the mass. The adjacent normal renal parenchyma is shown with a long arrow. (d) Angiomyolipoma; this incidental finding shows the typical appearance of a well-defined echogenic mass (arrows). Same patient as in Fig. 8.32c.
- Fig. 8.32 Benign renal masses. (a) Cyst in the left kidney (arrow) on CT showing a well-defined edge, imperceptible wall and uniform water density. The cyst shows no enhancement and was an incidental finding. L, liver; P, pancreas. (b) Angiomyolipoma seen as a well-defined mass (arrows) of fat density on CT. (c) Coronal T2-weighted MRI demonstrating a large angiomyolipoma in the central part of the right kidney (arrow).
- Intravenous urography
- Fig. 8.31 Plain radiograph of a partially calcified renal cell carcinoma.
- Computed tomography and magnetic resonance imaging
- Fig. 8.33 Renal cell carcinoma. The mass in the right kidney (long arrow) shows substantial enhancement and is invading the anterior wall of the right renal vein (short arrow).
- Fig. 8.34 Staging renal carcinoma. (a) CT scan showing a large tumour (T) in the left kidney from renal cell carcinoma and an enhancing metastasis (arrow) in the pancreas. (b) In another patient showing bilateral adrenal metastases (black arrows) and a nodal metastasis (white arrow). I, inferior vena cava.
- Fig. 8.35 Coronal MRI scan showing a huge left renal carcinoma (M) with tumour extending into the inferior vena cava (IVC) via the left renal vein (not seen on the view). The caval extension of tumour (arrowheads) extends to the top of the IVC (*). A, aorta.
- Fig. 8.36 Wilms’ tumour. A large heterogeneously enhancing mass arises from the posterior aspect of the left kidney (arrows). The remainder of the left kidney (LK) parenchyma lies anteriorly. RK, right kidney.
- Fig. 8.37 (a) Filling defect in an upper calix due to transitional cell carcinoma. (b) Ultrasound, in a different patient, demonstrating a tumour mass (between the cursors) projecting into the renal pelvis (P).
- Acute pyelonephritis
- Renal and perinephric abscesses
- Fig. 8.40 CT scan with intravenous contrast demonstrating multiple low attenuation fluid collections in the right renal cortex, consistent with multiple renal abscesses (arrows). LK, left kidney.
- Fig. 8.41 Perinephric abscess. (a) CT scan showing loculated fluid (arrow) with a thick enhancing wall surrounding the left kidney. (b) An abscess collection (A) lies posterior to the left kidney (K), with the enhancing kidney displaced anteriorly by the collection.
- Pyonephrosis
- Fig. 8.42 (a) Renal parenchymal calcification from tuberculosis on plain film. (b) In another patient, after contrast, there is irregularity of the calices (curved arrow) and stricture formation of the pelvis (arrowhead).
- Fig. 8.45 Renal trauma. (a) Axial CT demonstrating reduced perfusion in the midpole of the left kidney (arrow). Fluid is seen in the perinephric tissues. (b) Coronal reformat demonstrating a sharp cut-off of perfusion with complete loss of perfusion in the lower pole (black arrows). (c) Delayed oblique sagittal reformat demonstrating contrast in the collecting system (white arrow) and confirming no leak of contrast (black arrow).
- Fig. 8.46 Renal artery stenosis (arrow) demonstrated on a magnetic resonance angiogram. There is post-stenotic dilatation beyond the stenosis. The right kidney is small in size.
- Fig. 8.47 Chronic pyelonephritis secondary to stones on CT angiography. The right kidney is smaller than the left and contains multiple cystic areas following chronic infection from stone disease. The right renal artery is small in calibre (arrow). A, aorta; LK, left kidney.
- Renal failure from obstructive uropathy
- Renal failure from intrinsic renal disease (‘end-stage kidney’)
- Fig. 8.48 Intrinsic renal disease. Ultrasound of right kidney (longitudinal scan). The kidney is small and the cortical echoes are increased and therefore the central echo is less obvious. Normally, the liver is more echo-reflective than the renal cortex. K, kidney; L, liver.
- Acute tubular necrosis
- Bifid collecting systems
- Fig. 8.50 (a) Obstructed ectopic ureter. There is a bifid collecting system on the right. The upper moiety is obstructed and dilated causing deformity of the lower moiety. The obstructed moiety does not opacify. (b) Ultrasound, in a different patient, showing a dilated upper moiety (UM), with no remaining renal parenchyma. The lower moiety (LM) appears normal.
- Ectopic kidney
- Horseshoe kidney
- Fig. 8.51 Horseshoe kidneys. (a) The two kidneys are fused at their lower poles. The striking feature is the alteration in the axis of the kidneys: the lower calices are closer to the spine than the upper calices. The kidneys are rotated so that their pelvises point forward and the lower calices point medially. The medial aspects of the lower poles cannot be identified. (b) CT scan of a different patient, following intravenous contrast enhancement, showing fusion of the lower poles of the kidneys. The patient had disseminated peritoneal metastatic disease from ovarian cancer (*).
- Inherited cystic disease of the kidneys
- Fig. 8.52 Advanced polycystic disease in adults. (a) CT scan, taken after intravenous contrast enhancement, showing that both kidneys are greatly enlarged and almost entirely replaced by cysts of variable size. (b) Coronal T2-weighted MRI in another patient demonstrating multiple bilateral renal cysts as well as a few cysts in the liver (L). S, spleen.
- Renal agenesis
- Bladder tumours
- Fig. 8.53 Bladder neoplasm. (a) There is a large filling defect in the left side of the bladder from a transitional cell carcinoma. Note the obstructive dilatation of the left ureter. (b) Ultrasound scan from a different patient showing a small tumour within the bladder. (c) T2-weighted coronal MRI of the bladder tumour seen on ultrasound in (b). (d) Advanced stage bladder tumour arising from the left bladder wall and extending into the perivesical fat. Note the obstructed left ureter (arrow). B, bladder; T, tumour.
- Bladder diverticula
- Fig. 8.54 Bladder diverticula. (a) Cystogram showing numerous outpouchings from the bladder with a very large diverticulum projecting to the left. (b) Ultrasound of a large diverticulum (D) in a different patient.
- Bladder calcification
- Neurogenic bladder
- Fig. 8.55 Neurogenic bladder. The outline of the bladder is very irregular due to trabeculation of the bladder wall. The bladder has a small volume with an elongated shape; this appearance has been described as a ‘Christmas tree bladder’. There is a balloon catheter in the dilated posterior urethra.
- Trauma to the bladder and urethra
- Fig. 8.56 Rupture of the base of the bladder. Cystogram showing extravasation of contrast into the extraperitoneal space on the left, and deformity of the bladder due to surrounding haematoma and urine. There is a fracture of the right pubic bone.
- Prostatic enlargement
- Fig. 8.57 Early prostate cancer. Prostate carcinoma shown by TRUS. The tumour (T) is seen as a low echogenic ovoid mass in the right peripheral zone (arrow). R, rectum.
- Fig. 8.58 MRI of early prostate cancer. (a) T2-weighted MRI demonstrating focal low signal intensity in the left peripheral zone (arrow). (b) The lesion (arrow) is of high signal intensity on b 1000 DWI. (c) The lesion is of low signal intensity on the ADC map, consistent with restricted water diffusivity which is characteristic of prostate cancer (arrow).
- Fig. 8.59 Coronal T2-weighted MRI of the prostate gland (P) demonstrating invasion of the right seminal vesicle by carcinoma of the prostate (white arrow). Note the normal left seminal vesicle (black arrow).
- Prostatic calcification
- Fig. 8.60 Prostatic calcification. Numerous calculi just above the pubic symphysis are present in the prostate.
- Bladder outflow obstruction
- Urethral stricture
- Posterior urethral valves
- Fig. 8.63 (a) Ultrasound of a testis demonstrating a small seminoma (arrow). Several very bright echogenic specks of microcalcification are seen (arrowheads). (b) A hydrocoele (H) is demonstrated surrounding an otherwise normal testis (T).
- Fig. 8.64 MRI of an undescended right testis (arrow). The testis lies in the region of the right inguinal canal and appears of very high signal on the T2-weighted image with fat saturation. There is also a right inguinal hernia containing fat (*). B, bladder; R, rectum.
- Normal appearances
- Ultrasound
- Fig. 9.1 Normal abdominal scan of the uterus and vagina (longitudinal section). The central echo of the uterus (U) corresponds to the endometrial cavity; the uterus itself has a homogeneous echo texture. B, bladder; V, vagina.
- Fig. 9.2 Normal transvaginal ultrasound scan. (a) Longitudinal section through the uterus. Note the echogenic endometrial stripe between the measurement calipers. (b) Transverse section through the uterus. (c) Normal ovary. Several normal follicles are seen (arrows).
- Computed tomography
- Fig. 9.3 Normal uterus (long arrow) in a 49-year-old patient, on CT, following intravenous contrast enhancement. Note the oral contrast medium within loops of the small bowel (short arrow). B, bladder.
- Magnetic resonance imaging
- Fig. 9.4 Normal uterus on sagittal T2-weighted MRI. The endometrium (*) returns a high signal intensity. The cervix (white arrow) is in continuity with the lower uterine body. B, bladder; F, uterine fundus.
- Fig. 9.5 Axial MRI of a septate uterus, an anatomical variant. The endometrial cavity is divided into two compartments by a septum of myometrium (white arrow). Note the normal ovaries bilaterally (black arrows).
- Fig. 9.6 Oblique coronal T2-weighted MRI of a bicornuate uterus, with two divergent cornu (white arrows). The scar from a previous caesarean section is also seen (black arrow).
- Positron emission tomography/computed tomography
- Ultrasound
- Gynaecological pathology
- Pelvic masses
- Ovarian masses
- Ovarian cysts
- Fig. 9.7 Ovarian cyst. (a) Longitudinal ultrasound scan to the right of midline showing a 5cm cyst in the right ovary with no internal echoes. (b) Axial T2-weighted MRI scan showing a left-sided ovarian cyst (white arrow) with benign features. There is a small volume of free fluid in the pouch of Douglas (black arrows). U, uterus.
- Fig. 9.8 Polycystic ovary. Axial T2-weighted MRI demonstrating a left ovary (black arrow) which is large in size and has multiple small cysts arranged around the periphery of the ovary, in a characteristic ‘string of pearls’ distribution. B, bladder; C, cervix; R, rectum.
- Ovarian tumours
- Fig. 9.9 Ovarian carcinoma. (a) Longitudinal ultrasound scan showing a very large multilocular cystic tumour containing septa (S) and solid nodules (N). The lesion was a cystadenocarcinoma. (b) CT scan showing a large partly cystic, partly solid ovarian carcinoma (arrows). The tumour, which contains irregular areas of calcification, has invaded the right side of the bladder (B). The rectum is indicated by a curved arrow. (c) MRI scan showing a partly solid (arrows) and partly cystic tumour. The cystic component is of high signal intensity on this T2-weighted image. (d) FDG-PET/CT in a patient with disseminated ovarian cancer. Abnormally increased activity is seen in the chest, liver and peritoneum. Normal cardiac (C) and bladder (B) activity is demonstrated.
- Box 9.1 Morphological features of benign and malignant ovarian masses
- Fig. 9.10 Dermoid cyst. (a) CT scan showing the oval-shaped fat density of a dermoid cyst (D) containing calcified material (arrow). B, bladder. (b) Plain film of another patient showing well-developed teeth within the cyst.
- Fig. 9.11 Benign dermoid cyst. (a) Axial T1-weighted MRI demonstrating a complex cyst that contains high signal intensity material, indicating the possible presence of lipid (black arrow). An internal solid component is also seen (white arrow). (b) Axial T1-weighted image with fat saturation demonstrating an almost complete drop of signal intensity within the cyst, consistent with the presence of lipid (arrow). This confirms the diagnosis of a dermoid cyst. There was no enhancement of the internal solid component.
- Ovarian cysts
- Uterine masses
- Fibroids
- Fig. 9.12 (a) Transverse ultrasound scan showing a large fibroid in the uterus. Its extent is indicated by the arrows. (b) Sagittal T2-weighted MRI demonstrating several uterine fibroids (white arrows), which are of low signal intensity. The endometrial cavity is normal (black arrow). B, bladder; C, cervix.
- Adenomyosis
- Fig. 9.13 Adenomyosis. Sagittal T2-weighted MRI demonstrating a markedly widened junctional zone containing small cysts (between the white arrows). A normal section of junctional zone is seen in the region of the uterine fundus (black arrow). Two low signal intensity ovoid fibroids are also present in the fundus. B, bladder; C, cervix; R, rectum.
- Carcinoma of the cervix and body of the uterus
- Fig. 9.14 Carcinoma of the cervix. (a) Sagittal T2-weighted MRI scan showing a tumour confined to the cervix (arrows). E, endometrium. (b) Axial T2-weighted MRI in a different patient demonstrating a cervical tumour (T), which is confined to the cervix, with a thin layer of normal, low signal cervical tissue surrounding the tumour (arrows). B, bladder; R, rectum.
- Fig. 9.15 Advanced carcinoma of the cervix. (a) CT scan showing a large tumour (T) of the cervix invading the parametrium (arrows) and extending into the rectum posteriorly. (b) Sagittal T2-weighted MRI of the same patient. Note the tumour (T) extending down the vagina. B, bladder; E, endometrium; R, rectum.
- Fig. 9.16 Endometrial cancer. (a) Sagittal T2-weighted MRI demonstrating a polypoid tumour mass distending the endometrial cavity (arrow). (b) Oblique axial MRI in a different patient. The endometrial tumour mass is invading into the deep myometrium (arrow). B, bladder; C, cervix; V, vagina.
- Fibroids
- Fig. 9.17 Pelvic abscess. Ultrasound scan showing a highly complex cystic and solid hypoechoic mass with multiple locules (arrows) behind the bladder (B).
- Fig. 9.18 Endometriotic cyst. Transvaginal Doppler ultrasound demonstrating an adnexal cyst that has homogeneous internal echogenicity (white arrow), increased through transmission of sound (black arrow) and no Doppler signal within the cyst.
- Fig. 9.19 Bilateral endometriotic cysts. (a) Axial T1-weighted MRI showing haemorrhagic cysts in the pelvis (arrows), which have a relatively high signal on this sequence. (b) The cysts retain the high signal intensity on this fat-saturated T1 sequence, confirming the presence of blood. There is some variation in the signal intensity, a characteristic of endometriotic cysts.
- Fig. 9.20 Intrauterine contraceptive device (arrow) seen as a linear reflective echo within the uterine cavity, shown on a longitudinal ultrasound scan. C, cervix; F, uterine fundus.
- Fig. 9.21 Hysterosalpingogram. (a) Normal genital tract. Contrast has been injected to fill the uterus (U) and both fallopian tubes (vertical arrows). Free spill into the peritoneum has occurred to outline loops of bowel. Note the cannula in the cervical canal (horizontal arrow). (b) Hydrosalpinx. Both fallopian tubes are obstructed and dilated, the left one massively. There is no spill of contrast into the peritoneum.
- Ultrasound in the first trimester
- Fig. 9.22 Eleven-week-old fetus. The crown – rump length is indicated by the crosses. The fetus is seen in sagittal section and the head is clearly visible on the left and theh body to the right.
- Ultrasound in the second and third trimesters
- Placental imaging
- Fig. 9.23 Placental imaging. (a) Placenta seen on a longitudinal scan at 18 weeks’ gestation. The chorionic plate is seen as a thin line of bright echoes (arrows). (b) Axial T2-weighted MRI through the placenta (white arrow); myometrium is indicated by the black arrow. F, fetus.
- ‘Large for dates’ uterus
- Box 9.2 Causes of ‘large for dates’ uterus
- ‘Small for dates’ uterus: intrauterine growth retardation
- Ultrasound for karyotyping
- Fetal death
- Fig. 9.24 Ectopic pregnancy. Transvaginal scan in the transverse plane in a patient whose pregnancy test was positive. The uterus is seen containing no gestational sac and there is a predominantly cystic adnexal mass containing a fetal echo surrounded by amniotic fluid.
- Fig. 9.25 Ruptured ectopic pregnancy on CT. There is a left adnexal mass (*) with leakage of intravenous iodinated contrast (black arrow) due to bleeding. There is high density fluid in the pelvis and pouch of Douglas (white arrow) consistent with haemorrhagic ascites. U, uterus.
- PERITONEAL CAVITY
- Peritoneal cavity disorders
- Ascites
- Fig. 10.1 CT scan of ascites. (a) At the level of the kidneys. The fluid is seen surrounding the lower portion of the liver (L) and the bowel loops. (b) At the level of the liver and spleen (Sp). Note that the ascites cannot collect posteromedial to the right lobe of the liver because of the peritoneal reflections of the bare area (BA).
- Fig. 10.2 Ultrasound of ascites. (a) The ascites (A) appears as a transonic area. The liver is clearly seen surrounded by the ascitic fluid. K, right kidney; L, liver. (b) Only a very small amount of ascites is present in this patient. The ascites (arrows) lies between the liver and kidney in Morrison’s pouch.
- Peritoneal tumours
- Fig. 10.3 Intraperitoneal spread of ovarian carcinoma in three different patients. (a) CT demonstrating ascites (A) and an ‘omental cake’ of tumour deposits (arrows). There is hydronephrosis of the right kidney (RK). L, liver. (b) Diffusion-weighted MRI, b 1000 image, demonstrating the high signal intensity of peritoneal deposits (arrows). (c) Fused FDG-PET/CT demonstrating multiple FDG-avid peritoneal deposits (arrows) in the upper abdomen.
- Fig. 10.4 CT demonstrating a mass in the small bowel mesentery (arrows), which contains several dense calcifications. This is a secondary deposit from an ileal carcinoid tumour.
- Intraperitoneal abscesses
- Box 10.1 Diseases that mimic disseminated carcinoma of the ovary
- Ultrasound appearances
- Fig. 10.5 Intraperitoneal abscess shown by ultrasound in two separate patients. (a) A large complex mass (arrows) just above the bladder (B). This young man had Crohn’s disease. (b) A large abscess (arrows) lying directly beneath the liver (L).
- Computed tomography appearances
- Fig. 10.6 CT of postoperative intraperitoneal abscesses in three different patients. (a) Large abscess in the right side of the abdomen at the level of the umbilicus. Note the large air – fluid collection with a thin enhancing wall. The abscess displaces adjacent bowel loops (containing air and oral contrast). (b) A typical thick-walled abscess (arrows) containing both air and fluid. (c) A pelvic abscess (arrows) containing fluid (pus).
- Magnetic resonance imaging appearances
- Fig. 10.7 T2-weighted MRI scan in the sagittal plane demonstrating a pelvic abscess (white arrows) containing faecal material and air, which has formed a fistula with the anterior abdominal wall (black arrows).
- Radionuclide examination
- Fig. 10.8 Indium-111-labelled leucocyte scan of an intraperitoneal abscess. This abscess (arrow) followed small bowel surgery with subsequent anastomotic leak. Normal uptake is seen in the liver (L) and spleen (S).
- Ascites
- Peritoneal cavity disorders
- Box 10.2 Differential diagnoses in retroperitoneal masses
- Fig. 10.9 Diagram of anterior (downward pointing arrows) and posterior (upward pointing arrows) renal fascia. Ao, aorta; IVC, inferior vena cava.
- Imaging techniques
- Computed tomography
- Fig. 10.10 (a) CT scan of normal retroperitoneum. Note that the aorta (short arrow) and IVC (long arrow) are clearly outlined by fat and that there is a fat-containing space around the vessels. K, kidney. (b) There is a node at the upper limit of normal size in the left para-aortic space (arrow).
- Ultrasound
- Magnetic resonance imaging
- Fig. 10.11 Renal cell carcinoma invading the IVC. (a) T2-weighted MRI demonstrating a very large left renal tumour. The tumour has extended along the left renal vein (not shown) and into the IVC (arrow). (b) Coronal magnetic resonance venogram following gadolinium demonstrating the tongue of tumour tissue (arrow) in the IVC. A, aorta; RK, right kidney; T, tumour.
- Computed tomography
- Retroperitoneal lymphadenopathy
- Fig. 10.12 Lymphoma. (a) Several enlarged lymph nodes (arrows) are shown surrounding the contrast-enhanced aorta and IVC. (b) In this case, the para-aortic nodes have become confluent (arrows), forming a lobulated mass around the aorta (A). (c) Extensive nodal disease is seen infiltrating the small bowel mesentery (arrows).
- Adrenal gland disorders
- Fig. 10.13 Normal adrenal glands. (a) CT scan. Both adrenal glands (white arrows) are visible in this section. Note the different shape of the two glands. Ao, aorta; D, diaphragmatic crus; IVC, inferior vena cava; LK, left kidney; P, pancreas. (b) MRI scan showing the right and left adrenal glands (arrows), which have an intermediate signal intensity on these T2-weighted images.
- Fig. 10.14 Adrenal calcification shown by CT. (a) Heavily calcified right adrenal gland. (b) Heavily calcified left adrenal gland.
- Box 10.3 Causes of adrenal enlargement
- Functioning adrenal tumours
- Fig. 10.15 Functioning adrenal adenoma causing Cushing’s syndrome. (a) CT scan showing a 2 cm mass in the left adrenal gland with a density of < 10 Hounsfield units (arrow). (b) T1-weighted MRI scan also showing the lesion (arrow). K, kidney; P, pancreas.
- Fig. 10.16 Phaeochromocytoma. (a) CT scan showing a phaeochromocytoma (arrow) arising in the medial limb of the right adrenal gland. The inferior vena cava (IVC) lies anteriorly. K, kidney; L, liver; Sp, spleen. (b) T2-weighted MRI with fat saturation showing the same phaeochromocytoma (arrow) as in (a). GB, gall bladder. (c) Radioiodine-labelled MIBG scan of a phaeochromocytoma (arrows) in the left adrenal gland.
- Non-functioning adrenal masses
- Fig. 10.17 Adrenal cortical adenoma shown by chemical shift MRI. (a) An adrenal mass is demonstrated on the ‘in-phase’ image (arrow). (b) There is a marked drop in the signal intensity of the adrenal mass on the ‘out-of-phase’ image, confirming a benign cortical adenoma (arrow).
- Fig. 10.18 CT scan showing a right adrenal metastasis (arrow). (a) Non-contrast-enhanced study confirmed a density of 35 Hounsfield units. A, aorta; K, kidney; Sp, spleen; St, stomach. (b) Post contrast enhancement characteristics confirmed the presence of a non-adenomatous lesion.
- Fig. 10.19 Adrenocortical carcinoma. CT demonstrating a large heterogeneous mass arising in the left adrenal gland (between the arrows). Multiple liver and nodal metastases are also present (*).
- Fig. 10.20 Retroperitoneal liposarcoma. (a) Coronal CT scan showing a large fatty tumour (arrow) with minimal soft tissue and arising in the right retroperitoneum, consistent with a low grade liposarcoma. (b) Axial CT in a different patient demonstrating a left retroperitoneal liposarcoma with more soft tissue (between the white arrows). The patient also had a lymphoma in the right retroperitoneum, surrounding the right kidney (black arrow).
- Fig. 10.21 T2-weighted MRI demonstrating an intermediate signal intensity mass arising in the retroperitoneum (*), which is displacing the aorta (white arrow) and inferior vena cava (black arrow). A CT-guided percutaneous biopsy confirmed a benign ganglioneuroma.
- Fig. 10.22 Abdominal aortic aneurysm. (a) Ultrasound. Transverse scan showing a blood clot lining the wall (white arrows) within the aneurysm (black arrows). (b) CT scan with intravenous contrast enhancement. A 7 cm aneurysm (larger black and white arrows) with a lower density blood clot (small black arrows) lining the wall. The wall shows patches of calcification. The inferior vena cava (IVC) is displaced by the aneurysm. (c) CT angiography of the aorta. This sagittal reformat demonstrates a 3.5 cm fusiform aortic aneurysm (arrow).
- Fig. 10.23 CT scan of a leaking abdominal aortic aneurysm showing the aneurysm and the haemorrhage in the adjacent retroperitoneum (arrows).
- Fig. 10.24 CT scan of a large haematoma in the left iliopsoas muscle. Note the variable density, much of which is of lower density than the normal muscles.
- Fig. 10.25 Psoas abscess. CT scan showing a left psoas abscess (arrows). Note the thick wall, which has a rim of enhancement, and low density, fluid-like contents. Ps, normal right psoas muscle.
- Imaging techniques
- Plain bone radiographs
- Fig. 11.1 Normal long bones in (a) a child and (b) an adult. Increase in length takes place at the cartilagenous epiphyseal plate. In the growing child, calcification of cartilage occurs at the interface between the radiolucent growing cartilage and the bone to give the zone of provisional calcification, which is seen as a dense white line forming the ends of the shaft and surrounding the bony epiphyses. This calcified cartilage becomes converted to bone. (If there is temporary cessation of growth then the zone of provisional calcification may persist as a thin white line, known as a ‘growth line’, extending across the shaft of the bone.) As the child grows older the epiphyseal plate becomes thinner until, eventually, there is bony fusion of the epiphysis with the shaft.
- Fig. 11.2 Different types of periosteal reactions. (a) Smooth, lamellar, periosteal reaction on the radius and ulna in a case of non-accidental injury. (b) Spiculated (sunray) periosteal reaction in a case of osteogenic sarcoma (arrows). (c) ‘Onion skin’ periosteal reaction in a case of Ewing’s sarcoma (arrows). Here the periosteal new bone consists of several distinct layers. (d) Codman’s triangle in a case of osteogenic sarcoma. At the edge of the lesion the periosteal new bone is lifted up to form a cuff (arrow).
- Fig. 11.3 Cortical thickening. Note the thickened cortex in the midshaft of the tibia from old, healed osteomyelitis. Same patient as in Fig. 11.19a,b taken 1 year later.
- Fig. 11.19 Osteomyelitis. (a) An initial films reveals no abnormality. (b) A film taken 3 weeks later shows some destruction of the upper end of the tibia and an extensive periosteal reaction along the tibia, particularly the medial side (arrow). (c) Late acute osteomyelitis in another young child. The upper part of the humerus has separated to form a sequestrum. It is surrounded by an extensive periosteal reaction to form an involucrum. (d) Chronic osteomyelitis (Brodie’s abscess) showing a lucency in the tibia surrounded by substantial sclerosis.
- Fig. 11.4 Alteration of trabecular pattern in Paget’s disease involving the upper part of the tibia, leaving the lowest part of the tibia and the fibula unaffected. Note the coarse trabeculae. The other features of Paget’s disease – thickened cortex and bone expansion – are also present.
- Box 11.1 Radiographic signs of bone disease
- Ultrasound in musculoskeletal disease
- Fig. 11.5 Achilles tendon rupture. (a) The normal tendon shows a fibrillary pattern. (b) There is disruption of the fibrillary pattern due to a rupture of the tendon. The hypoechoic area (*) is due to a haematoma.
- Radionuclide bone imaging
- Fig. 11.6 (a,b) Normal radionuclide bone scan. (a) Adult. Note the radionuclide in the bladder. (b) Child. Note the bands of increased uptake in the epiphyseal plates where bone growth is occurring. (c) FDG-PET/CT demonstrates multiple, metabolically active bone metastases in a patient with breast cancer.
- Computed tomography in bone disease
- Box 11.2 Indications for technetium bone scanning
- Fig. 11.7 Osteoid osteoma that was not visible on plain films. (a) Bone scan (posterior view) showing a focal area of intense increased uptake in L3 (arrow). L, left. (b) Single photon emission computed tomography (SPECT) scan showing the increased uptake more clearly. (c) CT demonstrating the tumour arising in the pedicle (arrow).
- Box 11.3 Indications for bone CT
- Fig. 11.8 CT scan of a pelvis showing a large mass (arrows) due to a metastasis destroying the medial half of the right iliac bone with extension into the adjacent soft tissues.
- Box 11.2 Indications for technetium bone scanning
- Plain bone radiographs
- Magnetic resonance imaging in bone disease
- Fig. 11.9 MRI of bone tumours. (a) T1-weighted post contrast scan of osteosarcoma in the lower shaft and metaphysis of the left femur. The extent of tumour (arrows) within the bone and the soft tissue extension are both very well shown. The low signal in the medulla (*) is due to the calcified osteogenic component of the tumour. (b) The true extent of the tumour cannot be assessed from a plain film, although the plain film provides a more specific diagnosis, because the bone formation within the soft tissue extension (arrows) is obvious. (c) T2-weighted scan of lymphoma in the T10 vertebral body (arrow). The very high signal of the neoplastic tissue is evident even though there is no deformity of shape of the vertebral body.
- Box 11.4 Major indications for musculoskeletal MRI
- Fig. 11.10 T1-weighted MRI of soft tissue masses. (a) Soft tissue sarcoma producing an obvious soft tissue mass (arrows) in the medial compartment of the left thigh. (b) Large haematoma (arrows) in the medial compartment of the left thigh showing a mixed signal, including the characteristic high signal of recent haemorrhage on a T1-weighted sequence.
- Fig. 11.11 Localized lesions. (a) A well-defined sclerotic edge can be seen indicating a benign lesion – a fibrous cortical defect. (b) (Opposite) Bone island. There is a small, well-defined area of compact bone in the neck of the femur (arrow). This common finding is without significance. (c) An ill-defined edge – in this case a metastasis. This type of bone destruction is known as permeative. (d) A well-defined edge – in this case a metastasis in the shaft of the femur. (e) Destruction of the cortex indicating an aggressive lesion – another metastasis. (f) Expansion of the cortex due to fibrous dysplasia. (g) Periosteal reaction (arrow) – in this case osteomyelitis. (h) A lesion containing calcium (arrow) due to a cartilage tumour – in this case a chondrosarcoma.
- Box 11.5 Causes of a localized periosteal reaction adjacent to a lytic or sclerotic lesion
- Bone tumours
- Primary malignant tumours
- Fig. 11.12 Chondrosarcoma. (a) Plain film showing a large mass containing calcification arising from the pubic ramus. (b) CT showing the large mass containing calcium. There is also displacement of the bladder and rectum. (c) Axial MRI scan at the same level. Note that the calcification gives no signal. (d) MRI scan at a lower level showing the tumour extending into the gluteal muscles (arrow). B, bladder; R, rectum.
- Fig. 11.13 Giant cell tumour. An eccentric expanding lytic lesion has thinned the cortex crossed by strands of bone. The subarticular position is characteristic of this tumour.
- Benign tumours and tumour-like conditions
- Fig. 11.14 Enchondromas in the metacarpal, proximal and middle phalanges showing lytic areas that expand but do not breach the cortex.
- Fig. 11.15 Bone cyst. There is an expanding lesion crossed by strands of bone in the upper end of the humerus in a child. The lesion extends to, but does not cross, the epiphyseal plate.
- Fig. 11.16 Osteoid osteoma. (a) Plain film showing an area of sclerosis at the upper end of the tibia (arrows). (b) CT scan showing sclerosis with a central lucency known as a nidus (arrow).
- Fig. 11.17 Osteoma. A well-defined area of dense cortical bone is present below the right acetabulum.
- Primary malignant tumours
- Fig. 11.18 Osteomyelitis; radionuclide scans of knees. (a) A blood pool scan taken 1 minute after injection of radionuclide showing increased uptake in the upper part of the leg due to hyperaemia. (b) The delayed scan taken 3 hours later shows substantially increased uptake in the bone itself.
- Fig. 11.20 Osteomyelitis. T2-weighted MRI scan showing a high signal in the medulla of the tibia extending into the cortex and soft tissues. Same patient as Fig. 11.19d.
- Distinction of neoplasm from osteomyelitis
- Fig. 11.21 Bone infarct. There is calcification in the medulla of the lower end of the femur.
- Metastases
- Fig. 11.22 (a) Metastasis from a carcinoma of the kidney causing a large area of bone destruction with an ill-defined edge in the left iliac blade (arrow). (b) Fused FDG-PET/CT demonstrating the large soft tissue mass with peripheral FDG uptake (arrow) and central necrosis (*).
- Fig. 11.23 Sclerotic metastases showing scattered areas of increased density.
- Fig. 11.24 Multiple metastases from carcinoma of the breast showing both lytic and sclerotic areas.
- Fig. 11.25 Neuroblastoma. In this child’s humerus there are several lytic areas and a florid periosteal reaction.
- Fig. 11.26 Metastases. Radionuclide bone scan showing numerous discrete areas of increased uptake in the bones in a patient with carcinoma of the prostate.
- Fig. 11.27 Metastases from carcinoma of the prostate. Sagittal whole spine MRI scan showing low signal intensity in several vertebral bodies (arrows). Note the metastases also involve the posterior elements of two adjacent vertebrae (arrowheads).
- Fig. 11.28 Metastatic bone disease in a patient with breast cancer. (a) T1-weighted MRI and (b) diffusion-weighted MRI, with b value 1000, demonstrating a large area of metastatic bone disease in the left side of the sacrum (arrows).
- Fig. 11.29 Metastases. CT sagittal reconstruction in a patient with carcinoma of the breast showing multiple mixed, but mainly sclerotic, metastases in the thoracic and lumbar spine. There are pathological wedge fractures in two of the lower thoracic vertebrae (arrows).
- Multiple myeloma
- Fig. 11.30 Myeloma deposits causing multiple, well-defined lytic lesions.
- Lymphoma and leukaemia
- Multiple periosteal reactions
- Fig. 11.31 Hypertrophic pulmonary osteoarthropathy. There is a periosteal reaction which is present bilaterally along the shafts of the radius and ulna and the metacarpals. In this case, it was associated with a bronchial carcinoma.
- Box 11.6 Causes of multiple periosteal reactions
- Box 11.7 Causes of osteoporosis
- Osteoporosis
- Fig. 11.32 Senile osteoporosis. There is decreased bone density but the edge of the vertebral bodies are well demarcated. Note the partial collapse of several of the vertebral bodies and the widening of the disc spaces.
- Fig. 11.33 (a) Disuse osteoporosis due to osteomyelitis of the right calcaneum. The calcaneum is partly destroyed by infection. The remaining bones of the right foot show a marked reduction in bone density with well-defined cortex. Compare these bones with those in the normal left foot (b). (c) In this patient with paraplegia the osteoporosis has a spotty appearance.
- Screening for osteoporosis
- Rickets and osteomalacia
- Box 11.8 Causes of rickets and osteomalacia
- Fig. 11.34 (a) Dietary rickets showing widening and irregular mineralization of the metaphyses, which have a frayed appearance. There is reduced bone density and bowing of the limbs. (b) After commencement of vitamin D treatment, mineralization of the metaphyses has occurred.
- Fig. 11.35 Osteomalacia. (a) Looser’s zone showing the horizontal lucent band with sclerotic margins running through the cortex of the medial side of the upper femur (arrow). (b) There is decreased bone density and partial collapse of all the vertebral bodies to approximately the same extent.
- Hyperparathyroidism
- Fig. 11.36 Hyperparathyroidism. (a) Note the characteristic features of subperiosteal bone resorption (straight arrow), resorption of the tip of the terminal phalanx and the altered bone architecture. Arterial calcification is also present (curved arrow). (b) Brown tumour. There is a lytic area in the upper end of the humerus with a well-defined edge.
- Renal osteodystrophy
- Fig. 11.37 ‘Rugger jersey spine’ (renal osteodystrophy). There are sclerotic bands running across the upper and lower ends of the vertebral bodies of the lumbar spine (arrows).
- Fig. 11.38 Metastases from carcinoma of the prostate causing a widespread increase in bone density.
- Fig. 11.39 Osteopetrosis. There is a marked generalized increased bone density affecting all bones. There are multiple healed fractures, with a pin and plate in the left femur.
- Fig. 11.40 Myelosclerosis. A patchy increase in bone density in the humerus is seen. In this condition the bone marrow becomes replaced with bone.
- Paget’s disease
- Fig. 11.41 (a) Paget’s disease showing typical sclerosis with coarse trabeculae in the right side of the pelvis. Note that the width of the affected bones is increased. The pelvis is deformed consequent upon the bone softening. (b) Coronal reformat of CT in the same patient demonstrating coarse trabeculae, a thickened cortex and enlargement of the iliac blade. (c) Similar signs in the tibia of another patient. Note the bowing of the bone from softening.
- Fig. 11.42 Sarcoma in Paget’s disease. There is extensive bone destruction in the humeral head and shaft. Evidence of the underlying Paget’s disease can be seen.
- Haemolytic anaemia
- Marrow hyperplasia
- Fig. 11.43 Thalassaemia haemolytic anaemia. (a) Skull showing thickened diploë. (b) Hand; due to marrow expansion the bones are expanded and those trabeculae that remain are very thickened.
- Infarction and infection
- Marrow hyperplasia
- Sarcoidosis
- Fig. 11.44 Sarcoidosis, showing the characteristic lace-like trabecular pattern in the middle phalanx.
- Radiation-induced disease of bone
- Bone dysplasias
- Fig. 11.45 Diaphyseal aclasia. Several bony projections (exostoses) are seen arising around the knee, directed away from the joint. The opposite knee was similarly affected.
- Imaging techniques
- Plain film radiographs
- Fig. 12.1 Normal knee joint. Note the fabella (arrow), a sesamoid bone in the gastrocnemius. The ‘joint space’ consists of articular cartilage and synovial fluid.
- Magnetic resonance imaging
- Arthrography
- Ultrasound
- Plain film radiographs
- Arthritis
- Signs indicating the presence of arthritis
- Signs that point to the cause of arthritis
- Fig. 12.2 Erosions. Areas of bone destruction are seen affecting the articular cortex of the metacarpophalangeal joint. A typical erosion is arrowed. The joint space is also narrowed.
- Box 12.1 Causes of erosions
- Fig. 12.15 Coronal MRI scan showing avascular necrosis of both femoral heads. The changes on the left are very severe and advanced. The changes in the right hip are relatively early and show a rim of low signal demarcating the ischaemic area (arrows).
- Fig. 12.16 Post-traumatic avascular necrosis. A pin has been inserted because of a subcapital fracture of the femoral neck (arrow), which occurred 10 months before this film was taken. Avascular necrosis has occurred in the head of the femur, which has become sclerotic.
- Diagnosis of arthritis
- Rheumatoid arthritis
- Fig. 12.3 Early rheumatoid arthritis. Small erosions are present in the articular cortex (arrows) and there is soft tissue swelling around the proximal interphalangeal joints.
- Fig. 12.4 Advanced rheumatoid arthritis (arthritis mutilans). There is extensive destruction of the articular cortex of the metacarpophalangeal joints with ulnar deviation of the fingers. Fusion of the carpal bones and wrist joint has occurred.
- Fig. 12.5 Rheumatoid arthritis. Uniform loss of joint space is seen in this hip joint. Sclerosis is also present due to associated osteoarthritis.
- Fig. 12.6 Rheumatoid arthritis – atlantoaxial subluxation. C1 is displaced anteriorly upon C2. The distance between the arch of the atlas and the odontoid peg (arrow) is increased from the normal value (2mm) to 8mm. This is the same patient whose hand is illustrated in Fig. 12.4.
- Role of radiology in rheumatoid arthritis
- Other erosive arthropathies
- Fig. 12.7 Psoriatic arthropathy. There are extensive erosive changes affecting the interphalangeal joints but sparing the metacarpophalangeal joints.
- Gout
- Fig. 12.8 Gout. (a) Erosion: there is a typical well-defined erosion with an overhanging edge (arrow) at the metatarsophalangeal joint of the big toe. (b) Tophi: these are large soft tissue swellings. A good example is seen around the proximal interphalangeal joint of the index finger. Several erosions are present (one is arrowed).
- Calcium pyrophosphate dihydrate crystal deposition disease
- Fig. 12.9 Chondrocalcinosis. Calcification can be seen in the menisci in the knee (arrows).
- Osteoarthritis
- Fig. 12.10 Advanced osteoarthritis. (a) Note the narrowed superior part of the joint space of the hip, subchondral sclerosis and cyst formation and osteophytes. (b) Similar changes are seen in the metatarsophalangeal joint of the big toe, which is known as hallux rigidus.
- Table 12.1 Comparison of osteoarthritis and rheumatoid arthritis
- Haemophilia and bleeding disorders
- Fig. 12.11 Haemophilia. Subchondral cysts have formed, caused by repeated haemorrhages into the joint. Note the soft tissue swelling around the joint and the deep intercondylar notch – a characteristic feature of haemophilia.
- Pyogenic arthritis
- Fig. 12.12 Pyogenic arthritis. (a) The initial film of the wrist was normal. (b) Film taken 3 weeks later showing destruction of the carpal bones and bases of the metacarpals.
- Tuberculous arthritis
- Fig. 12.13 Tuberculous arthritis of the shoulder. Note the striking osteoporosis and erosion of the humeral head.
- Fig. 12.14 Avascular necrosis. There is fragmentation with some sclerosis of both femoral heads.
- Box 12.2 Causes of avascular necrosis
- Fig. 12.17 Post-traumatic avascular necrosis. The ununited scaphoid fracture shows a sclerotic proximal pole (arrow) due to avascular necrosis of this part of the bone.
- Osteochondritis
- Fig. 12.18 Perthe’s disease. The right femoral epiphysis (arrow) in this child is sclerotic and flattened. Compare it with the normal left side.
- Fig. 12.19 Osteochondritis dissecans. (a) A fragment (arrow) has become separated from the articular cortex of the medial femoral condyle. (b) Coronal CT scan through an ankle showing a small osteochondritis dissecans fragment (horizontal arrow) separated from the rest of the talus with a well-corticated defect in the underlying bone (vertical arrow). (c) MRI scan of the knee showing an osteochondritis defect (arrows) of the medial femoral condyle.
- Menisci
- Fig. 12.20 Tear of the medial meniscus. Sagittal MRI through the medial part of the knee joint showing a tear in the posterior horn of the medial meniscus. The anterior horn appears normal.
- Cruciate ligaments
- Fig. 12.21 (a) Normal anterior cruciate ligament is shown as a low signal band in the intercondylar notch (arrows) on this MRI scan. (b) With a tear the ligament is disrupted.
- Collateral ligaments
- Supraspinatus tendon tears
- Fig. 12.22 Ultrasound of the supraspinatus tendon. (a) Normal tendon (arrow) demonstrated at the level of insertion into the greater tuberosity of humerus (H). (b) The supraspinatus tendon is thin (long arrow) and there is a tear (short arrow) shown as low echogenicity, between the two caliper crosses. H, head of humerus.
- Fig. 12.23 (a) Normal shoulder MRI showing the supraspinatus tendon inserting into the greater tuberosity of the humerus. (b) Supraspinatus tendon tear. MRI showing complete disruption of the supraspinatus tendon (white arrow) with fluid in the subacromial bursa (arrowhead) and oedema of the adjacent deltoid muscle (black arrow). (c) MRI arthrogram demonstrating the high signal intensity of gadolinium injected into the joint space (arrow).
- Calcific tendonitis
- Fig. 12.24 (a) Supraspinatus tendinitis. Calcification is present in the supraspinatus tendon (arrow). (b) Ultrasound image demonstrates focal calcification (long arrow) near the insertion of the supraspinatus tendon (which is shown between the two short arrows). H, head of humerus.
- Neuropathic joint
- Fig. 12.25 Diabetic foot. There is resorption of the heads of the second and third metatarsals and bases of the proximal phalanges causing disorganization of the metatarsophalangeal joints. The patient had a peripheral neuropathy with an anaesthetic foot.
- Synovial sarcoma (synovioma)
- Slipped femoral epiphysis
- Fig. 12.26 Slipped femoral epiphysis. (a, b) Lateral views of the hips showing the right femoral epiphysis displaced posteriorly (compare with the normal left side). (c) Frontal view of the same patient showing the right femoral epiphysis displaced downwards. (d) A line drawn along the lateral border of the femoral neck normally intersects a portion of the capital epiphysis whereas this does not occur on the side with slip.
- Developmental dysplasia of the hip
- Fig. 12.27 Developmental dysplasia of the right hip. The right femoral epiphysis (arrow) is smaller than on the normal left side and it does not lie within the acetabulum. Note the sloping roof of the right acetabulum (dashed line).
- Osteitis condensans ilii
- Fig. 12.28 Osteitis condensans ilii, anteroposterior view. Sclerosis is seen in both iliac bones just adjacent to the sacroiliac joints. The joints themselves, however, are normal. The patient was a young woman who had borne children.
- Scleroderma
- Fig. 12.29 Scleroderma. Extensive soft tissue calcification is present as well as atrophy of soft tissues at the ends of the fingers.
- Imaging techniques
- Fig. 13.1 Normal vertebral anatomy. Surface-shaded CT reconstructions of lumbar vertebrae in (a) axial and (b) sagittal views. 1, pedicles; 2, spinous process; 3, facet joint made up of superior (3a) and inferior (3b) articular facets; 4, transverse process; 5, disc space; 6, vertebral body; 7, lamina; c, central canal; e, exit foramen.
- Fig. 13.2 Plain films of normal lumbar spine. (a) Frontal view. 1, pedicles; 2, spinous process; 3, facet joint; 4, transverse process. (b) Lateral view. 1, pedicles; 2, spinous process; 3, facet joint; 4, vertebral body; 5, disc space. Note how the height of the disc spaces increases from L1 to L5 with the exception of the L5/S1 disc space which is normally narrower than the one above.
- Fig. 13.3 MRI of the lumbar spine. (a) Normal T1-weighted scan. The discs and spinal cord are of intermediate signal. (b) Normal T2-weighted scan. The discs and CSF appear as high signal. The L5/S1 disc has lost height and is reduced in signal compared to the other discs, in keeping with degenerative changes (arrow). (c) Axial T2-weighted scan through the L3/L4 disc space. At this level, the L3 nerve roots are in the exit foramina (short arrow) and the L4 nerve roots have moved to the edge of the dural sac (long arrow) in the lateral recesses prior to exiting the spinal canal at the level below. p, psoas muscle. (d) Sagittal T1-weighted scan showing focal areas of low signal within multiple vertebral bodies (some marked with arrows) due to metastatic breast cancer.
- Radiographic signs of spinal abnormality
- Disc space narrowing
- Fig. 13.4 Disc space narrowing caused by disc degenerative changes between L3 and L4. Note the osteophytes (arrows) and sclerosis of the adjoining surfaces of the vertebral bodies.
- Collapse of vertebral bodies
- Box 13.1 Causes of collapsed vertebral bodies
- Fig. 13.5 Collapsed vertebra. (a) Metastasis (arrow) causing complete collapse of the vertebral body. The adjacent vertebral discs are unaffected. (Continued on following page) (b) Osteomyelitis. The disc space is narrowed and there is destruction of the surfaces of the adjacent vertebral bodies (arrows). (c) Traumatic collapse. Note the concave superior surface of the collapsed vertebral body. Some fragments have been extruded anteriorly (arrow). (d) Osteoporotic collapse. There is decreased bone density with a collapse of a vertebral body due to a compression fracture. (e) Collapse due to eosinophil granuloma. In this child the vertebral body is so collapsed that it resembles a thin disc (arrow).
- Pedicle abnormalities
- Fig. 13.6 Destruction of the pedicles due to metastatic renal cell carcinoma. (a) The pedicles of L1 have both been destroyed, as has the right pedicle of T12. Arrows point to representative normal pedicles (P). (b) MRI scan in the same patient showing extensive tumour in the vertebral body and a posterior mass of tumour (arrows) which is compressing the dural sac. (c) CT scan in a different patient with prostatic metastases showing sclerosis of the left pedicle of a lower thoracic vertebra together with sclerosis in the vertebral body and transverse process.
- Fig. 13.29 Spinal cord compression. (a) T2-weighted MRI scan showing metastases from a breast carcinoma in the body and pedicle of T3 causing compression of the spinal cord. (b) Axial T1-weighted image of a different patient showing a breast cancer metastasis arising from the right pedicle and casusing extradural compression of the cord. There is a fluid–fluid level (arrow) in the metastasis due to bleeding within the tumour.
- Dense vertebrae
- Fig. 13.7 Dense vertebra (arrow) due to metastases from carcinoma of the breast.
- Fig. 13.8 Paget’s disease. Note the increased density and coarse trabeculae in the vertebral bodies (arrows). They are also wider than the normal ones.
- Fig. 13.9 Haemangioma. Vertical striations are present in this normal-sized vertebra (arrowhead).
- Disc space narrowing
- Spinal trauma
- Fig. 13.10 Normal cervical spine radiographs. (a) Anteroposterior, (b) lateral and (c) open mouth (peg) views. Note the lateral view includes the C7/T1 junction.
- Fig. 13.11 Spinal cord injury. T2-weighted MRI showing high signal in the spinal cord due to oedema and haemorrhage (arrow).
- Fig. 13.12 Normal cervical spine showing lines to check alignment. Line 1 runs along the anterior border of the vertebral bodies and corresponds to the anterior longitudinal ligament. Line 2 runs along the posterior border of the vertebral bodies (posterior longitudinal ligament). Line 3 runs along the junction of the laminae and spinous processes (ligamentum flavum). Line 2 indicates the anterior extent and line 3 the posterior extent of the spinal canal. There is a normal soft tissue distance between the anterior border of the spine and the posterior border of the airway (double-headed arrows).
- Fig. 13.13 Cervical spine injury. (a) On this midline CT scan there is a step in the alignment at the C5/C6 level. Soft tissue swelling is seen anteriorly at this level (arrow). (b) A section more laterally showing facet dislocation with overlap of the facets (arrow). (c) T2-weighted MRI showing injury to the intervertebral disc and displacement at the C6 level which has caused some spinal cord compression and oedema (arrow). High signal haemorrhage is seen anteriorly.
- Box 13.2 Causes of dense vertebrae
- Fig. 13.14 Atlanto-axial subluxation.(a) Plain film taken with the neck flexed showing widening of the space between the dens of C2 and the anterior aspect of C1 (double arrow) in a patient with rheumatoid arthritis. (b) T1-weighted MRI showing widening of the atlanto-axial space in the same patient even when supine in the scanner.
- Fig. 13.15 Diagram to show the three columns of the spine. The anterior column includes the anterior longitudinal ligament and anterior two-thirds of the vertebral body (1). The middle column includes the posterior third of the vertebral body and the posterior longitudinal ligament. The posterior column includes the pedicles (2), laminae (3) and spinous processes (4). Redrawn from Dr T. Jaspan, with permission.
- Fig. 13.16 Flexion teardrop. Sagittal reformat of a CT scan showing a hyperflexion teardrop fracture at C6. The anterior column was in compression causing the fracture and the posterior part of the vertebral body is retropulsed (note disrupted posterior vertebral body line) into the canal with potential cord injury.
- Fig. 13.17 Hyperextension injuries. (a) Radiograph showing an extension teardrop fracture of C2 (arrow) with minimal associated prevertebral swelling (haematoma). (b) ‘Hangman’s fracture’: axial CT showing the bilateral pars interarticularis fractures (arrows).
- Fig. 13.18 Jefferson’s fracture. (a) Plain film showing overlap of the articular pillars of C1 beyond the margins of the C2 vertebral body (dashed lines) due to a burst fracture of C1 (compare with the normal radiograph in Fig. 13.10). (b) Axial CT showing the fractures of the posterior arch more clearly together with fractures of the anterior arch (arrows).
- Fig. 13.19 Burst fracture of L1 caused by falling 6 m from a ladder. (a) Plain film showing a compression fracture of the body of L1. (b) Axial CT and (c) sagittal CT showing more clearly fragments displaced into the spinal canal (arrows). The arrowhead points to a fracture of the lamina. All three spinal columns are fractured. (d) T2-weighted MRI showing the posterior fragments causing cord compression (arrow).
- Degenerative spinal disease
- Fig. 13.20 Cervical spondylosis. (a) Axial T2-weighted MRI of the cervical spine showing a combination of disc protusion and oteophytes causing narrowing of the right exit foramen (arrow). (b) Sagittal oblique T2-weighted MRI of a different patient with a previous anterior spinal fusion (arrowhead) and a disc protrusion causing narrowing of the C6/C7 exit foramen (arrow).
- Disc herniation
- Lumbar disc herniation.
- Fig. 13.21 MRI scans of disc herniation. (a) Sagittal T2-weighted scan showing a large posterior herniation of the L4/L5 disc (arrow). (b) Axial T1-weighted scan of an L5/S1 disc showing a disc herniation compressing the adjacent nerve root. The opposite equivalent nerve root can be clearly seen.
- Fig. 13.22 Postoperative fibrosis. T1-weighted MRI scans at the L5/S1 level in a patient with sciatica following L5/S1 laminectomy 6 months previously. (a) The scan shows a normal right S1 nerve root (curved arrow), but around the left S1 nerve root there is a mass (arrows) which could be either fibrosis or recurrent disc herniation. (b) After gadolinium the mass enhances, indicating that it is fibrosis. A disc herniation would not enhance.
- Lumbar disc herniation.
- Fig. 13.23 Spondylolisthesis. (a) Lateral view. There is forward slip of L5 upon S1. The dashed lines that mark the posterior aspects of the vertebral bodies should form a smooth curve. The defect in the pars interarticularis is arrowed. (b) CT scan showing a defect in the pars interarticularis (arrow) in another patient.
- Fig. 13.24 Tuberculosis of the spine. (a) Plain film showing destruction of the vertebral bodies and the intervening discs with the formation of a sharp angulation (gibbus). One vertebral body is almost completely destroyed (arrow) and there is destruction of the upper part of the one below it. (b) T2-weighted MRI in another patient showing destruction of the intervertebral disc and part of the vertebral body below it. A large inflammatory mass is protruding into the spinal canal causing compression of the cauda equina (arrow).
- Fig. 13.25 Bacterial discitis. (a) Plain film of discitis at C6/C7 with loss of intervertebral height and non-visualization of the normally corticated adjacent endplate. (b) Sagittal T2-weighted MRI of a different patient with high signal pus in the L3/L4 disc space. (c) Sagittal T1-weighted MRI, post contrast, with intense enhancement of the adjacent vertebral bodies and also between the spinous processes posteriorly.
- Fig. 13.26 Ankylosing spondylitis. (a) The sacroiliac joints have an irregular fuzzy outline. (b) With advanced disease the whole spine becomes fused (‘bamboo spine’). Note that the sacroiliac joints are also fused. (c) CT in another patient showing a transverse fracture through the disc space in the midlumbar spine (arrows). The spine above and below the fracture is fused.
- Fig. 13.27 Congenital spinal anomolies. (a) Sagittal T2-weighted MRI showing the conus is located abnormally low at approximately L5/S1 (long arrow) with incomplete formation of the low lumbosacral posterior elements (wide arrow). There is also a segmentation anomaly at T7–T9 with poorly formed intervertebral discs (arrowhead). (b) Frontal radiograph of an infant showing an early scoliosis due to a left hemivertebra at T8 – note the number of ribs compared to pedicles.
- Fig. 13.28 Spinal cord compression; schematic axial and sagittal sections. (a) Normal view. B, vertebral body; C, spinal cord; EDF, extradural fat; L, lamina; P, pedicle; SP, spinous process; TP, transverse process; TS, thecal sac. (b) Extradural metastatic tumour. Extrinsic compression of the thecal sac and spinal cord, which are compressed and displaced away from the tumour. (c) Intradural extramedullary tumour. The tumour is contained within the undisplaced thecal sac but compresses and displaces the spinal cord. (d) Intradural intramedullary tumour. The spinal cord is expanded but undisplaced with little or no visualization of the CSF in the thecal sac around the spinal cord. Redrawn from Dr T. Jaspan with permission.
- Fig. 13.30 Intradural neurofibroma. T2-weighted MRI scan showing the tumour at the T6/T7 level compressing and displacing the spinal cord anteriorly (arrows).
- Fig. 13.31 Intradural intramedullary lesion. (a) Sagittal T2-weighted MRI scan showing an ovoid mass (ependyoma) at the level of the conus. (b) Axial T2-weighted MRI scan below the level of the conus showing the mass within the intradural space surrounded by the cauda equina nerve roots (arrows).
- Fig. 13.32 Chiari I malformation. The tips of the cerebellar tonsils extend through the foramen magnum (dashed line) to reach the level of C2.
- Fig. 13.33 T2-weighted MRI showing a plaque of demyelination (arrow) in a patient with multiple sclerosis.
- Imaging techniques
- Plain radiographs
- Fig. 14.1 Value of two views for demonstrating the position of fractures. (a) The fractures of the radius and ulna show little displacement on the frontal projection. (b) The lateral view, however, shows a marked angulation.
- Box 14.1 Types of fracture
- Computed tomography
- Fig. 14.2 Fracture of the pelvis. (a) A section through the acetabular roof demonstrating an anterior column injury with displaced bony fragments. (b) A coronal section showing the fracture of the acetabulum extending to the iliac bone superiorly. The fractures and their displacement were much better demonstrated with CT than with radiographs of the pelvis.
- Fig. 14.3 CT scanning in a spinal fracture. (a) A comminuted fracture of C7 with displacement of a large bone fragment (arrow) into the spinal canal. (b) Sagittal reconstruction also shows the fractured vertebra and displaced fragment (arrow).
- Fig. 14.4 Multiple fractures. Three-dimensional MDCT reformat demonstrating a complex pelvic fracture (arrows), useful in aiding operative planning.
- Magnetic resonance imaging
- Fig. 14.5 Coronal MRI of the wrist. (a) T1-weighted image and (b) STIR image, showing a low signal intensity fracture line in the waist of the scaphoid (arrows). The STIR image shows surrounding haemorrhage and oedema as high signal either side of the fracture.
- Fig. 14.6 Bone bruise. MRI in a patient who suffered severe soft tissue damage to the lateral side of his knee. The high signal in the medial femoral condyle (arrows) is due to a bone bruise. The plain films of the knee showed no bony injury.
- Fig. 14.7 Rupture of patella tendon. (a) MRI showing diffuse high signal in the region of the patella tendon. (b) Normal patella tendon (arrows) for comparison.
- Radionuclide bone scanning
- Fig. 14.8 Radionuclide bone scans in trauma. (a) Fracture of the scaphoid. There is increased activity in the scaphoid in this patient who suffered continuing pain after trauma to the wrist. In spite of normal x-rays, the bone scan indicates there is a fracture that was not visible on the radiographs. (b) Fractures in five of the ribs on the right. The distribution of increased uptake is diagnostic of injury. (c) Insufficiency fracture. There is increased uptake in the sacrum in this elderly woman who had a normal pelvic x-ray. B, isotope in the bladder.
- Imaging fractures
- Fig. 14.9 Fracture of the head of the radius appearing as a lucent line.
- Fig. 14.10 Fracture of the lower ulnar metaphysis appearing as a sclerotic line (small black arrow).
- Fig. 14.11 Step in cortex and interruption of bony trabeculae (arrow) in a Colles’ fracture.
- Fig. 14.12 Greenstick fracture of the lower end of the radius in a child. There is buckling of the cortex (arrows).
- Fig. 14.13 Elbow effusion with fracture of the radial head. (a) The anterior and posterior fat pads (arrows) are displaced away from the humerus, which almost invariably means a fracture is present. (b) Oblique view in this patient showing the fracture of the radial head (arrow) which was only demonstrated on the oblique view.
- Imaging dislocations
- Further plain film views
- Fig. 14.14 Oblique view demonstrating a fracture. (a) Anteroposterior and (b) lateral views in this child’s ankle do not show an obvious fracture. (c) Oblique view clearly demonstrating the fracture (arrow).
- Fig. 14.15 Stress view demonstrating ligamentous rupture. Inversion stress on the ankle opens up the lateral joint indicating rupture of the lateral ligaments.
- Box 14.2 Radiographic signs of fracture
- Fig. 14.16 Flexion and extension views demonstrating a fracture. (a) An extension view of the cervical spine does not reveal a fracture. (b) A flexion view clearly shows the fracture of the arch of C2 (arrows).
- Fig. 14.17 Delayed films demonstrating a fracture. (a) Films taken immediately after the injury did not show a fracture. (b) Films taken 2 weeks after the injury show a fracture through the scaphoid (arrow).
- Plain radiographs
- Salter–Harris classification
- Fig. 14.18 (a)
- Fig. 14.18 (b, c) Two examples of Salter–Harris type II fractures. Note that in both examples the fracture runs through the metaphysis as well as through the epiphyseal plate (arrows).
- Fig. 14.19 Fracture of the clavicle. This common fracture usually occurs in the outer half of the clavicle. Upward displacement of the medial fragment is frequently seen, as in this example.
- Fig. 14.20 Acromioclavicular dislocation. Capsular and ligamentous tears of the acromioclavicular ligaments allow the outer end of the clavicle to be displaced upward relative to the medial aspect of the acromion process (arrow).
- Fig. 14.21 Fracture of the neck of the humerus (black arrows) is a common fracture in the elderly and may be overlooked clinically if it is impacted. The greater tuberosity is also fractured (white arrow) in this example.
- Fig. 14.22 Anterior dislocation of the shoulder. The head of the humerus is displaced inferior and anterior to the glenoid fossa to lie beneath the coracoid process.
- Fig. 14.23 Anterior dislocation of the shoulder may be associated with a fracture of the greater tuberosity.
- Fig. 14.24 Posterior dislocation of the shoulder is often a consequence of an electric shock or epileptic seizure. (a) The dislocation may be difficult to see on the frontal view. Note the internal rotation of the humerus and lack of congruity of the humeral head with the glenoid. Note the ‘lightbulb’ appearance of the humeral head. (b) Lateral view showing the humeral head behind the posterior rim of the glenoid fossa beneath the spine of the scapula.
- Fig. 14.25 Dislocation of the elbow. The common form is backward and lateral displacement of the radius and ulna.
- Fig. 14.26 Supracondylar fractures. (a) With minor displacement and (b) with severe displacement. These fractures occur in children and are potentially dangerous because of possible injury to the brachial artery and nerve damage.
- Fig. 14.27 Epicondylar fracture showing medial epicondyle separation. Fractures of the epicondyles occur in children before the epiphyses fuse fully.
- Fig. 14.28 Colles’ fracture is common, especially in the elderly. It is a fracture through the lower end of the radius and sometimes the ulnar styloid is avulsed in addition, as in this example. (a) Anteroposterior view. (b) Lateral view showing posterior displacement and angulation giving rise to the ‘dinner fork’ deformity.
- Fig. 14.29 Smith’s fracture is a fracture of the lower radius with the reverse deformity to a Colles’ fracture. It has anterior displacement and angulation. (a) Anteroposterior view. (b) Lateral view.
- Fig. 14.30 Fracture through the lower radial epiphysis resulting in separation of the epiphysis (Salter–Harris I fracture).
- Fig. 14.31 Fractures of wrist bones. (a) Scaphoid fractures occur in young adults following a fall on the outstretched hand. They are serious injuries because if missed non-union or avascular necrosis may supervene. The fracture (arrow), as in this example, is usually across the waist of the scaphoid. (b) Triquetral fracture – a flake fracture detached from the posterior aspect of the triquetral (arrow) is seen only on the lateral view.
- Fig. 14.32 Dislocation of carpal bones. (a, b) The lower end of the radius, lunate (L) and capitate (C) are normally in a straight line. (c) If wrist ligaments are ruptured, the carpal bones, as in this case, may be dislocated posterior to the lunate and the lower radius. Alternatively, and often difficult to differentiate, is anterior dislocation of the lunate.
- Fig. 14.33 Bennet’s fracture is a fracture through the base of the thumb metacarpal. (a, b) Two views showing a fracture (arrow) which, as in this example, often involves the articular surface of the carpometacarpal joint. It invariably requires internal fixation.
- Fig. 14.34 A boxer’s fracture (arrow) is an injury due to punching. It is a fracture through the shaft of the little finger metacarpal and is often angulated.
- Fig. 14.35 Finger injuries. Various fractures and dislocations occur. This patient, who suffered an industrial accident, has a dislocation of the proximal interphalangeal joint of the ring finger with a fracture through the base of the middle phalanx (upward arrow). There is also a fracture through the posterior aspect of the base of the terminal phalanx of the little finger (downward arrow). Such fractures may need special treatment.
- Fig. 14.36 Fractures through the pubic rami (arrows) are common in the elderly.
- Fig. 14.37 Fractures through the pelvic ring occur with severe trauma. In this example, there is obvious separation of the pubic symphysis. The inevitably accompanying further fractures/dislocations of the pelvic bones and sacroiliac joints often require CT for their demonstration.
- Fig. 14.38 Fractures through the femoral neck are common in the elderly and may result from minor trauma. The radiographic signs in some instances may be subtle. (a) A fracture through the femoral neck interrupts Shenton’s line. (b) Shenton’s line is a curved line formed by the top of the obturator ring and the medial aspect of the neck of the femur (the interruption of Shenton’s line is shown by the dots). (c) Impacted fracture (arrows) causing only a sclerotic line and disruption of the trabecular architecture. (d) Intertrochanteric fracture (arrows) between the greater and lesser trochanters. Intertrochanteric fractures are less prone to subsequent complications than other femoral neck fractures.
- Fig. 14.39 Fracture of the patella. There is separation of the fragments and an effusion is present, seen as an opacity in the suprapatellar pouch.
- Fig. 14.40 Dislocation of the patella. The patella is dislocated laterally out of the intercondylar groove.
- Fig. 14.41 Fat in haemarthrosis. With a knee fracture, fat is often released from the bone marrow and a fat–fluid level may be seen in the suprapatella pouch (black arrows). There is a fracture of the tibial plateau seen as a sclerotic band (white arrow).
- Fig. 14.42 Tibial plateau fractures. A lateral tibial plateau fracture can occur when a car strikes the outer side of the knee (‘bumper fracture’). (a) The tibial plateau is fragmented and is driven down into the tibia. (b) CT showing the depression, which requires surgical treatment. (c) A similar injury can occur to the medial tibial plateau.
- Fig. 14.43 Ankle fractures. Various fractures occur involving the lateral, medial or both malleoli, with or without disruption of the talus in the ankle mortice (see also Fig. 14.15). Soft tissue swelling is usually seen in association with ankle fractures. (a) Fracture of lateral malleolus without displacement of talus. (b) Fracture of the medial malleolus. (c) Anteroposterior and (d) lateral views of a fracture of the lateral malleolus with a lateral shift of the talus indicating ligamentous damage. Note the soft tissue swelling associated with all these fractures.
- Fig. 14.44 Fracture of the lateral and medial malleoli with a lateral shift of the talus.
- Fig. 14.45 Salter–Harris type I fracture of the ankle (arrows) showing widening of the growth (epiphyseal) plate.
- Fig. 14.46 Fracture through the neck of the talus.
- Fig. 14.47 Calcaneal fractures are jumping injuries and may be undisplaced or result in compression, causing flattening of the calcaneum. This can be appreciated by a reduction in Bohler’s angle to less than 20°. (a) Bohler’s angle, shown here in a normal subject, is the angle made by a line across the anterior process of the calcaneum intersecting with a line parallel to the axis of the posterior portion of the calcaneum. (b) Fracture causing flattening and fragmentation of the calcaneum. (c) CT in the same patient showing depressed fragments and complete disruption of the subtalar joint and the fracture involving the calcaneocuboid joint.
- Fig. 14.48 Tarsometatarsal dislocation. Lateral dislocation of the metatarsals through the tarsometatarsal joint is known as Lisfranc’s fracture. There is a step between the medial border of the medial cuneiform and the medial border of the base of the second metatarsal (arrows point to these two landmarks). The second to fifth metatarsals are dislocated laterally.
- Stress fracture
- Fig. 14.50 ‘March fracture’. (a) The initial film at the time of injury showing a faint lucent line at the base of the second metatarsal (arrow). (b) Follow-up film at 2 weeks showing a marked periosteal reaction and callus formation at the site of the stress fracture (arrows).
- Fig. 14.51 Stress fractures. (a) In this calcaneum there is sclerosis adjacent to the stress fracture (arrow). (b, c) MRI of a calcaneal stress fracture in a different patient. (b) T1-weighted image demonstrating a low signal intensity sclerotic stress fracture (arrow). (c) STIR sequence demonstrating bright oedema (*) surrounding the fracture (arrow).
- Fig. 14.49 (a) Fractures of the base of the fifth metatarsal appear as a horizontal line across the base of the metatarsal (arrow). (b) They should not be confused with a normal apophysis (arrow) which is seen as a sliver of bone parallel to the axis of the metatarsal.
- Fig. 14.52 Stress fracture. Radionuclide bone scan showing increased uptake in the tibia (arrow) of this athlete with pain in the leg. The radiographs at the time of the scan were normal.
- Insufficiency fracture
- Pathological fracture
- Fig. 14.53 Pathological fracture. (a) A fracture has occurred through one of many lytic metastases from a carcinoma of the breast. (b) This fracture, in another patient, has occurred through an area of bone destruction due to myeloma.
- Fig. 14.54 Paget’s disease showing incomplete fractures, known as infractions, of the lateral aspect of the femur. Note the marked thickening of the cortex and bowing of the femur.
- Non-accidental injury
- Fig. 14.55 Non-accidental injury. (a) The fracture through the humerus is recent and, apart from the young age of the baby, is an unremarkable spiral fracture. (b) However the chest x-ray taken at the same time shows healing posterior rib fractures (arrows).
- Fig. 14.56 Non-accidental injury. (a) Multiplicity of fractures. There is a recent fracture of the humerus with florid callus formation. The fractures of the radius and ulna are of longer duration and show healing with organized callus. (b) Periosteal reaction along the shaft of the tibia (arrow) from previous trauma with haemorrhage under the periosteum. There has been recent trauma to the lower end of the femur with marked periosteal reaction. (c) Metaphyseal fractures (arrows) and sclerosis around the knee.
- Box 14.3 Signs of non-accidental injury in children
- Avulsion fractures
- Fig. 14.57 Avulsion fracture. (a) In this example, the avulsed ischial spine appears as a bone fragment adjacent to the ischium (black arrow). (b) MRI showing the non-union of the avulsed fragment (arrow).
- Imaging techniques
- Fig. 15.1 Myeloma. Multiple well-defined lytic lesions of various sizes are seen in all areas of the skull vault.
- Computed tomography
- Fig. 15.2 (a) Diagram of the axial, coronal and sagittal planes. (b) Corresponding CT images of a normal brain.
- Fig. 15.33 Depressed fracture. Axial unenhanced CT on (a) brain and (b) bone window settings. The depressed fracture and bone fragments are more clearly seen on the bone window settings. Such fractures may require surgical elevation.
- Contrast enhancement for computed tomography
- Computed tomography angiography
- Fig. 15.3 Surface-shaded CT angiograms. (a) Sagittal and (b) axial images created from a contrast-enhanced CT scan showing the normal arteries and veins of the brain.
- Normal head computed tomography
- Fig. 15.4 (a–g) Normal head CT images. The levels at which the sections were taken are indicated in the diagram (h). C, cerebellar hemisphere; CP, choroid plexus; CR, corona radiata; Dor sel, dorsum sellae; III, third ventricle; Int capsule, internal capsule; LV, lateral ventricle; O, occipital lobe; P, pituitary gland; Pe, petrous bone; Syl fissure, Sylvian fissure; T, temporal lobe; Th, thalamus; V, vermis. (i) (Opposite) Surface-shaded CT angiogram with the major intracranial arteries labelled. ACA, anterior cerebral artery; ACommA, anterior communicating artery; AICA, anterior inferior cerebellar artery; bas art, basilar artery; CarotidA, carotid artery; MCA, middle cerebral artery; PCA, posterior cerebral artery; PCommA, posterior communicating artery; PICA, posterior inferior cerebellar artery; SCA, superior cerebellar artery; VertA, vertebral artery.
- Box 15.1 Intracranial enhancement on computed tomography and magnetic resonance imaging
- Abnormal head computed tomography
- Abnormal tissue density
- Fig. 15.5 Types of oedema. (a) Unenhanced CT image demonstating vasogenic oedema around a hyperdense brain metastasis (arrow). Note how the oedema extends through the white matter but spares the overlying grey matter cortex. (b) Unenhanced CT demonstrating a wedge-shaped area of cytotoxic oedema from an ischaemic stroke involving the middle cerebral artery territory and both the grey matter cortex and the underlying white matter. Both are associated with mass effect causing distortion of the lateral ventricles.
- Fig. 15.21 Acute parenchymal haemorrhage. CT scan showing the haematoma as a high density area with local mass effect (H) in the left frontal lobe.
- Fig. 15.22 Subarachnoid haemorrhage. (a) High density subarachnoid blood can be seen in the basal cisterns outlining the brain stem (long arrow), the Sylvian fissures (short arrow) and within the fourth ventricle (curved arrow).
- Fig. 15.25 Cerebral abscess. (a) Post contrast CT scan showing a right frontal ring-enhancing lesion with surrounding vasogenic oedema (arrow). (b) DWI showing the contents of an abscess (arrow) with restricted diffusion in keeping with pus.
- Mass effect
- Fig. 15.6 Brain herniation. Unenhanced CT scans showing subfalcine and downward transtentorial herniation due to an acute subdural haematoma. (a) In subfalcine herniation there is a shift of brain and ventricles across the midline (dashed line). (b) In downward transtentorial herniation there is obliteration of the normal CSF-containing basal cisterns and herniation of the medial temporal lobe over the tentorium cerebellum. u, uncus.
- Enlargement of the ventricles
- Fig. 15.7 Obstructive hydrocephalus. Axial CT images performed at the level of the lateral ventricles (a) and more inferiorly at the level of the temporal horns (b). The lateral ventricles including the temporal horns (arrows) are dilated but the fourth ventricle (*) is normal in size. The CSF-filled sulci normally seen along the convexeties of the cerebral hemispheres are also effaced. The hydrocephalus was due to a tumour (t) obstructing the aqueduct, which connects the third and fourth ventricles.
- Fig. 15.29 Dementia imaging. (a) Coronal T2-weighted scan showing generalized cerebral atrophy with widening of the sulci and more advanced atrophy of both hippocampi (arrows) secondary to Alzheimer’s disease. (b) CT scan showing severe atrophy of the frontal lobes anteriorly compared to the parietal lobes posteriorly due to Pick’s disease.
- Abnormal tissue density
- Fig. 15.8 Normal brain MRI. The images are axial sections at the level of the lateral ventricles. (a) T2-weighted image. (b) FLAIR image. (c) A midline sagittal section (T1-weighted).
- Fig. 15.9 Magnetic resonance angiography (MRA). The arteries at the base of the brain, the circle of Willis, are very well shown by MRA without the use of any contrast agent.
- Fig. 15.10 DWI in stroke. (a) An unenhanced CT image showing low attenuation in the right frontal lobe and basal ganglia (arrow). (b) Diffusion-weighted MRI showing bright signal indicating the extent of restricted diffusion due to an acute infarct; it is more extensive anteriorly (arrow).
- Fig. 15.11 Diffusion tractography image derived from diffusion data showing the structural connectivity of the brain where white matter fibres running in the same orientation are ascribed the same colour. Courtesy of Dr Maddigan, St George’s Hospital, London.
- Contrast enhancement for magnetic resonance imaging
- Fig. 15.15 Metastases. (a) Enhanced CT scan showing several metastases as rounded areas of increased density in the cerebral and cerebellar hemispheres. (b) Enhanced T1-weighted MRI scan showing a ring-enhancing cerebellar metastasis (arrow).
- Abnormal magnetic resonance imaging of the brain
- Fig. 15.12 Cerebral haemorrhage on MRI. A mixed signal haemorrhage in the midbrain on (a) axial T2-weighted and (b) sagittal T1-weighted sequences due to acute blood and chronic blood products (haemosiderin) in a cavernous haemangioma (arrows).
- Fig. 15.13 Neurosonography. (a) Normal coronal section taken through the anterior fontanelle in a neonate. (b) Coronal section showing bilateral subependymal haemorrhages (arrows). The lateral ventricles are dilated. C, cavum septum pellucidum; III, third ventricle; LV, lateral ventricle.
- Brain tumours
- Glioma
- Fig. 15.14 Glioma. (a) CT scan, post intravenous contrast, showing an irregular enhancing mass (arrows) with surrounding low attenuation involving both frontal lobes and the corpus callosum, in keeping with a high grade glioma (glioblastoma multiforme). (b) MRI scan (coronal FLAIR sequence) in a different patient, showing signal change in both the grey and white matter (arrow) with mild mass effect in a glioma (anaplastic astrocytoma).
- Brain metastases
- Meningioma
- Fig. 15.16 Meningioma. (a) CT scan pre contrast showing a partially calcified mass in the anterior cranial fossa. There is low density CSF between the mass and the displaced grey matter cortex (arrow) indicating the tumour is extra-axial in location. (b) CT post contrast showing prominent enhancement of the mass typical of a meningioma. Also note the normally enhancing vessels which are also extra-axial and between the mass and brain.
- Acoustic neuroma
- Fig. 15.17 Vestibular schwannoma. (a) High resolution T2-weighted sequence through the internal auditory meati showing a soft tissue mass on the left (arrow) extending into the cerebellopontine cistern. (b) Post gadolinium enhancement; the small schwannoma (arrow) in the left internal auditory canal is clearly demonstrated.
- Pituitary tumours
- Fig. 15.18 Pituitary tumour. (a) CT scan after contrast showing a mass in the pituitary fossa which enhances vividly (small arrows). (b) Sagittal T1 post contrast MRI and (c) coronal T1 MRI showing a macroadenoma (arrows) expanding the pituitary fossa and extending superiorly to touch the optic chiasm in the suprasellar cistern.
- Glioma
- Cerebral infarction
- Fig. 15.19 Dense artery sign. Unenhanced CT showing acute thrombus in the right middle cerebral artery (arrow).
- Fig. 15.20 Cerebral infarction. (a) Initial CT scan a few hours after the onset of symptoms showing low attenuation in the posterior cerebral artery territory with swelling causing effacement of the local sulci (arrow). (b) CT scan a month later showing low attenuation gliotic change in the same territory and atrophy causing localized expansion of the lateral ventricle and widening of the sulci (arrow).
- Intracerebral haemorrhage
- Subarachnoid haemorrhage
- Fig. 15.23 Arteriovenous malformation. (a) Carotid angiogram showing a collection of large abnormal vessels (large open arrow) supplied by the middle cerebral artery (horizontal arrow). On this injection the posterior cerebral artery (vertical arrow), but not the anterior cerebral artery, has filled. (b) Subtraction. With this technique the shadowing due to the bones has almost been eliminated so that the contrast-filled vessels stand out more clearly.
- Fig. 15.24 Acute viral encephalitis. (a) Unenhanced CT showing low density in the right temporal lobe (arrow) in a distribution unusual for an acute infarct. (b) Axial FLAIR sequence showing high signal oedema and swelling in the medial temporal lobe and hippocampus. (c) DWI showing acute restricted diffusion of acute encephalitis in the right temporal lobe and inferior frontal lobe.
- Fig. 15.26 Neurocysticercosis. (a) Axial and (b) coronal T2-weighted MRI showing multiple cysts in the brain and subarachnoid space. Several of the cysts contain a low signal dot which is the headpart (scolex) of the parasite.
- Fig. 15.27 Multiple sclerosis. (a) Axial FLAIR sequence at the level of the lateral ventricles. (b) Parasagittal T2-weighted MRI and (continued on following page) (c) axial T2-weighted MRI through the posterior fossa. The T2-weighted MRI scans show plaques of demyelination as high signal in the white matter, particularly along the margins of the lateral ventricles and immediately next to cortical grey matter. Bilateral plaques also seen in the middle cerebellar peduncles (arrows). (d) Post contrast T1 sequence showing a broken ring of enhancement (arrow) typical of demyelination.
- Fig. 15.28 Cerebral atrophy. Axial T2-weighted MRI showing prominence of the ventricles and generalized widening of the cerebral sulci in keeping with age-related atrophy.
- Extracerebral haematoma
- Fig. 15.30 Extracerebral haematoma. CT scan showing a high density lentiform-shaped extra-axial collection.
- Fig. 15.31 Subdural haematomas on CT. (a) High density extra-axial collection paralleling the surface of the brain due to acute subdural haematoma. (b) Bilateral isodense subdural haematomas causing mass effect and effacement of the sulci from the subacute subdural haematomas. (c) Bilateral low density extra-axial collections causing mass effect from chronic subdural haematomas.
- Intracerebral lesion
- Fig. 15.32 Contusion. CT scan showing irregular high density blood in the inferior left frontal lobe due to contusions. There is also a right-sided extradural haematoma (arrow).
- Fracture
- Fig. 15.34 Pneumocephalus. CT scan showing low density air in the sulci of the brain from a basal skull fracture involving the sinuses.
- Sinuses
- Fig. 16.1 Mucosal thickening and a fluid level. In the right antrum, thickening of the mucosa (double-headed arrow) results in the sinus no longer having a thin outline. The horizontal line in the left antrum on this erect film (arrow) indicates a fluid level that remains horizontal even when the patient’s head is tilted.
- Fig. 16.2 Coronal CT scan. (a) Normal sinuses. Note the excellent demonstration of the bony margins. The arrow points to the middle meatus into which the maxillary antrum and frontal, anterior and middle ethmoid sinuses drain. The region where all these sinuses drain is known as the osteomeatal complex. A, maxillary antrum; E, ethmoid sinus; I, inferior turbinate; M, middle turbinate. (b) Sinusitis. Mucosal thickening prevents drainage of the sinuses. Both antra are almost opaque. The arrows indicate mucosal thickening in the antra.
- Opaque sinus
- Fig. 16.3 Carcinoma of the antrum. CT scan showing a large mass arising from the left antrum destroying its bony walls and extending into the adjacent soft tissues. The arrows point to the extent of the tumour. The opposite antrum is normal.
- Box 16.1 Causes of opaque sinus
- Fig. 16.4 Nasopharyngeal carcinoma. (a) CT scan showing a mass (M) in the nasopharynx on the left extending into the soft tissues of the postnasal space and eroding the skull base (black arrows). Note how the tumour obliterates the fossa of Rosenmuller and eustachian recess, which are shown on the normal right side (white arrows). (b) MRI scan in another patient clearly showing the extent of the tumour (arrow). The tumour is blocking the left eustachian tube and fluid is accumulating in the mastoid (*).
- Fig. 16.13 Lymphadenopathy. (a) There is a large lymph node (N) and several additional enlarged nodes (arrows) caused by metastases from a carcinoma of the floor of the mouth. (b) The lymph node mass (M) in this patient was due to infection.
- Fig. 16.5 Optic nerve glioma. CT scan showing a soft tissue mass arising from the optic nerve (O.N.). The opposite orbit demonstrates the normal anatomy.
- Fig. 16.6 Carcinoma of the ethmoid sinus invading the orbit and causing proptosis. The tumour is arrowed.
- Fig. 16.7 Thyroid eye disease. CT scan through the orbits showing enlargement of the extraocular muscles, particularly the medial rectus (arrows). ON; optic nerve.
- Blowout fracture
- Fig. 16.8 Blowout fracture of the orbit; CT coronal reconstruction. (a) A patient with a blow to the eye showing a soft tissue opacity in the roof of the antrum (arrow). It is difficult to appreciate the fracture of the orbital floor. (b) A patient with trauma to the side of the face showing disruption of the floor of the orbit and fractures of the lateral and medial walls of the orbit, as well as the lateral wall of the antrum (arrows). There is herniation of orbital contents into the antrum, which is opaque.
- Fig. 16.9 Pleomorphic adenoma of the parotid gland. (a) Ultrasound showing a lobulated parotid mass (arrow). (b) MRI scan showing a high signal intensity mass in the right parotid (arrow), which proved to be a pleomorphic adenoma.
- Sialography
- Fig. 16.10 Normal parotid sialogram. Note the long duct of even calibre and the fine branching of the ducts within the gland.
- Fig. 16.11 Sialectasis. There is dilatation of the ducts due to a stone (arrow) in the main parotid duct.
- Fig. 16.12 Ultrasound-guided FNA of a cervical lymph node showing the aspiration needle (arrow) within a necrotic lymph node (*). The carotid artery (C) is also visualized.
- Larynx
- Fig. 16.14 Carcinoma of the larynx. CT scan showing a large tumour (T) in the larynx that has destroyed the vocal cords and invaded the thyroid cartilage (arrow). A lymph node metastasis is present (L). C, carotid artery; V, jugular vein.
- Thyroid imaging
- Fig. 16.15 Normal ultrasound of thyroid. The two lobes of the thyroid (arrows) lie on either side of the trachea (T).
- Fig. 16.16 Multinodular goitre. The enlarged thyroid almost surrounds the trachea (T) and enhances avidly after intravenous contrast showing many nodules of varying size.
- Fig. 16.17 Ultrasound of thyroid nodules. (a) Ultrasound of a complex malignant thyroid nodule with cystic areas (*) and bright foci that indicate punctate calcification (arrow), which is associated with papillary and medullary thyroid cancer. (b) Ultrasound showing several hyperplastic nodules in the right lobe of the thyroid with a typical spongiform texture (arrows). The common carotid artery (C) and internal jugular vein (V) are also demonstrated.
- Fig. 16.18 Carcinoma of the thyroid. 131I scan in a patient who had undergone thyroidectomy for carcinoma of the thyroid and then developed bone metastases. (a) Anterior and (b) posterior view. This image was acquired during a therapeutic dose of 131I and shows residual uptake in the thyroid bed (*) as well as multiple bone metastases (one of which is shown with an arrow).
- Parathyroid imaging
- Fig. 16.19 Parathyroid adenoma. (a) Transverse ultrasound of a parathyroid adenoma (calipers) seen behind the left lobe of the thyroid gland (*). The common carotid artery (C) is also demonstrated. (b) CT of another patient showing an avidly enhancing right parathyroid adenoma (arrow).
- Fig. 16.20 Subtraction scintigraphy showing a single right upper pole adenoma (arrow). (a) 99mTc Pertechnetate acquisition. (b) 99mTc Sestimibi acquisition. (c) Subtraction image. (d) Statistical difference image.
- Fig. 16.21 CT of the neck showing an ectopic right retrotracheal adenoma (arrow) lying next to the eosophagus (*).
- Diagnostic vascular angiography
- Arteriography
- Fig. 17.1 Seldinger technique for catheterizing blood vessels. The femoral artery or vein are the usual vessels used. (a) A needle is inserted through the skin into the blood vessel. (b) A guidewire is passed through the needle into the lumen of the vessel. (c) The needle is withdrawn, leaving the guidewire in the lumen of the vessel. (d) A catheter is threaded over the guidewire and passed into the lumen of the vessel. (e) The guidewire is withdrawn, leaving the catheter in position in the lumen of the vessel.
- Fig. 17.2 Digital subtraction arteriogram following an intra-arterial injection of contrast medium. On the subtracted image (a) the bones and soft tissues are barely visible compared to the unsubtracted image (b). The angiogram shows a patent popliteal artery (thin arrow) with a short segment occlusion proximal to the trifurcation (curved arrow).
- Magnetic resonance angiography
- Fig. 17.3 MRA of the carotid arteries showing a short stenosis in the right internal carotid artery (long arrow). A normal internal carotid artery is seen on the left (arrowhead).
- Fig. 17.4 MRA. (a) Contrast angiogram showing a normal abdominal aorta and its branches. (b) Contrast angiogram showing the superior mesenteric (horizontal arrow) and portal (upward pointing arrow) veins.
- Computed tomography angiography
- Box 17.1 Major indications for arteriography
- Fig. 17.5 CT angiogram. Reconstruction from many thin axial sections following an intravenous injection of contrast demonstrating an aortic aneurysm (arrow). Calcification is seen in the wall of the arteries (arrowhead).
- Ultrasound of the arterial system
- Ultrasound venography
- Contrast venography
- Arteriography
- Interventional radiology
- Angioplasty and stents
- Fig. 17.6 Percutaneous transluminal angioplasty. (a) Preliminary arteriogram showing an occlusion in the left superficial femoral artery (arrow). (b) Following the angioplasty, the lumen has been restored.
- Fig. 17.7 Percutaneous angioplasty balloon catheters. (a) The catheter prior to inflating the balloon. (b) The catheter with the balloon distended as it would be if it were inside the artery.
- Fig. 17.8 Stent which has been placed in the liver to make a connection between the portal and systemic venous systems in the transjugular intrahepatic portosystemic shunt procedure.
- Fig. 17.9 (a) Digital subtraction arteriogram (DSA) of the abdominal aorta showing a large aneurysm (arrow). (b) DSA post stent graft. The covered stent (short arrows), acting as an endoskeleton, has excluded the aneurysm from the circulation by creating a seal proximally below the renal arteries (long arrows) and distally in the iliacs. This depressurizes the aneurysmal sac and reduces the risk of rupture.
- Fig. 17.10 Diagram demonstrating the techniques of conventional and subintimal angioplasty. In subintimal angioplasty, the catheter is passed into the subintimal plane of the vessel, not in the lumen of the vessel. The balloon is then inflated. The principle is to create a new lumen in the subintimal plane rather than re-open the native lumen. PTA, percutaneuos transluminal angioplasty.
- Therapeutic embolization
- Fig. 17.11 Therapeutic embolization. (a) Arteriogram prior to embolization showing patent internal iliac arteries (arrows) in a patient with uncontrollable bleeding from a large bladder tumour. (b) Following embolization, both iliac arteries are occluded. The arrows point to the level of occlusion.
- Fig. 17.12 Therapeutic embolization. (a) CT scan in a patient with a large intrahepatic haematoma (H) following a road traffic accident. (b) Selective hepatic anteriogram showing a false aneurysm (arrow) which was the site of bleeding. Note the haematoma (H) compressing the liver substance. (c) A branch of the hepatic artery supplying the aneurysm has been occluded with coils (arrows) and the aneurysm no longer fills.
- Fig. 17.13 Arteriovenous malformation occlusion. (a) Carotid angiogram showing a large arteriovenous malformation. (b) After occlusion of the feeding vessels with cyanoacrylate glue the malformation is obliterated.
- Fig. 17.14 Embolization. (a) CT scan in a patient with a subarachnoid haemorrhage showing high density blood in the Sylvian fissures (arrows) and anterior hemispheric fissure (curved arrow). There is also hydrocephalus. (b) Right internal carotid angiogram showing an anterior communicating artery aneurysm (arrow). (c) The arrows on the three-dimensional formatted image point to the neck of the aneurysm. (d) The aneurysm is obliterated after it is occluded with metal coils (arrow).
- Therapeutic ablation
- Vascular catheterization for infusion
- Inferior vena cava filters
- Fig. 17.15 Inferior vena cava filter. (a) Plain film showing the bird’s nest filter in place. (b) An inferior vena cavogram showing a large thrombus (arrows) trapped by the filter.
- Percutaneous needle biopsy
- Fig. 17.16 Needle biopsy of an enlarged para-aortic lymph node under CT control with the patient prone. (a) An enlarged lymph node (arrows) is seen to the left of the abdominal aorta (Ao) at the level of the kidneys (K). (b) The tip of an 18-gauge cutting needle has been placed in the enlarged lymph node. The tissue obtained confirmed that the lesion was a metastasis from a germ cell tumour of the testis.
- Percutaneous drainage of abscesses and other fluid collections
- Fig. 17.17 (a) An abdominal abscess in the right iliac fossa secondary to appendicitis. Small pockets of air are seen in the collection (arrow). (b) A percutaneous drainage catheter (partially seen) has been inserted into the collection (arrowhead) which is decreasing in size.
- Fig. 17.18 Pancreatic pseudocyst drainage. (a) CT scan showing a collection involving the body of the pancreas, which developed following acute pancreatitis. (b) A drainage catheter has deliberately been inserted through the stomach into the collection (to encourage the development of an internal rather than a cutaneous fistula), which has decreased significantly in size.
- Transjugular liver biopsy
- Transjugular intrahepatic portosystemic shunt
- Fig. 17.19 Transjugular intrahepatic portosystemic shunt (TIPSS). (a) A catheter has been passed from the jugular vein in the neck through the heart into a hepatic vein and then pushed through the liver parenchyma into a portal vein. A retrograde injection is made outlining the portal vein and its tributaries. Note the gastro-oesophageal varices. (b) A connection between the portal vein and a large hepatic vein has been established and a stent inserted. Its position is shown by the arrows. Note the varices no longer fill (in part due to deliberate occlusion).
- Interventional radiology of the gastrointestinal tract
- Fig. 17.20 (a) A single-contrast, water-soluble enema, demonstrating a stricture in the distal sigmoid colon (arrow). (b) The stricture has been crossed using endoscopic and fluoroscopic guidance, and stented (arrowheads). This allows decompression of the bowel, allowing the patient to undergo elective rather than emergency surgery.
- Interventional radiology of the urinary tract
- Interventional radiology of the biliary tract
- Fig. 17.21 Endoscopic removal of stones in the common bile duct (CBD). A balloon catheter has been passed into the CBD after endoscopic intubation of the papilla of Vater. The stones were then pulled out of the CBD. B, balloon; S, stone.
- Fig. 17.22 Percutaneous insertion of a stent to bypass an obstruction in the common bile duct (CBD). (a) A biliary duct has been punctured in the liver and contrast injected to delineate the biliary tree. (b) A guidewire is inserted through the needle over which a catheter is passed to cross the stricture (arrow) and thence through the ampulla into the bowel. Note the decompressed CBD distal to the stricture (arrowhead). (c) A self-expanding metal stent is then inserted over the guidewire (arrow) and deployed across the stricture. Note the radio-opaque marker delineating the distal end of the stent. (d) Completion cholangiogram demonstrating free flow of bile through the stent (arrow) into the duodenum.
- Angioplasty and stents
- Appendix Computed Tomography Anatomy of the Abdomen
- Index
UM RAFBÆKUR Á HEIMKAUP.IS
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