Slide 1

 

Attempt first, then scroll Down For the answers

 

 

 

 

 

 

Slide 2

(A) Bennett's fracture-dislocation of the base of the thumb. Note that the oblique fracture extends into the joint. Note also the radial and proximal displacement of the metacarpal shaft, due to contraction of the abductor pollicis longus. Extra-articular fracture (arrow, B) generally does not require surgical fixation

 

Slide 3

Scapholunate dissociation. PA view of the wrist in ulnar deviation (A) shows abnormal widening of the scapholunate distance (greater than 4 mm), consistent with disruption of the scapholunate ligament. View in radial deviation (B) demonstrates no significant abnormality; the widening is not apparent.

 

Slide 4

This is a hangman's fracture with subluxation of C2 upon C3 and widely displaced fracture in the neural arch.

 

Slide 5

Hill–Sachs deformity of the humerus. Internal rotation view of the shoulder (A) shows a notch in the posterolateral aspect of the humeral head (arrow). (B) Axial T2-weighted MRI from another patient who previously suffered an anterior shoulder dislocation demonstrates a Hill–Sachs defect (arrow). The Hill–Sachs defect is seen as a notch in the posterolateral humeral head above or at the level of the coracoid process.

 

Slide 6

Morgagni hernia with acute gastric outlet obstruction. A: Transverse CT image in a 54-year-old man who presented with nausea and vomiting demonstrates herniation of the dilated stomach to the right of midline, posteriorly across the anterior diaphragm (arrows). B: Reformatted coronal CT image reveals a large right foramen of Morgagni defect in the anterior diaphragm (arrows at margins of defect), with herniation of the distal stomach, abdominal fat, and a small portion of nondilated colon (arrowheads). C: Reformatted sagittal CT image shows a transition between the dilated stomach and nondilated duodenum (arrows) coursing across the defect from the chest to the abdomen. Hernia was surgically reduced and the defect repaired.

 

Slide 7

Part of a panoramic radiograph showing an ameloblastoma, which appears as an expansile, multilocular radiolucency involving the left body of the mandible.

 

Slide 8

Thyroglossal cyst at base of tongue.

 

Slide 9

Ependymoma of the filum terminate and conus medullaris. Sagittal T2W (A) and (B) T1W post gadolinium-enhanced MRIs of the lumbar spine showing an expansile enhancing intraspinal mass and central signal change in the spinal cord above.

 

Slide 10

   Neuroblastoma. (A) Chest radiography shows posterior mass on the right in a child with chest pain and no clinical features of infection. (B) CT chest (noncontrast) shows calcification in the mass adjacent to the spine. There was no evidence of extradural extension on MRI.

 

Slide 11

   Ovarian teratomas. (A) Pelvic US in an 8 year old girl showing a mainly anechoic cystic mass, over 10 cm in diameter, with a more solid component posteriorly. (B) Coronal CT reformatted image in a 10 year old girl showing a cystic mass lesion superior to the bladder with (possibly tooth-like) calcification seen peripherally on the right side of the mass.

 

Slide 12

   Sagittal synostosis. (A) Brain CT and (B) lateral scout view showing the typical ‘boat-shaped’ skull or scaphocephaly of sagittal synostosis

 

Slide 13

   Thyroglossal duct cyst. (A) Axial T1-weighted spin-echo and (B) T2-weighted fast spin-echo images show a well-defined high signal intensity thyroglossal duct cyst just anterior to the hyoid bone.

 

Slide 14

   Vascular calcifications

 

Slide 15

Figure 47.8  Periosteal chondroma. (A) Lateral radiograph of the distal femur showing a calcified surface lesion. (B) Axial fat-suppressed T2-weighted fast spin-echo MRI showing a hyperintense lobulated lesion, without medullary infiltration.

 

Slide 16

Acute deep venous system thrombosis. (A). CT in a young woman presenting obtunded postpartum. The internal cerebral veins are dense and expanded (short arrow). The straight sinus is also hyperdense (long arrow) whereas the superior sagittal sinus is normal in appearance (black arrow). The surrounding thalami and basal ganglia appear as low density. There is mild hydrocephalus due to a combination of thalamic swelling and impaired CSF absorption. (B) Axial T2 confirms oedema in deep venous territory. Note thrombosed internal cerebral veins return low signal mimicking flow void, due to deoxyhaemoglobin in acute thrombus (arrows). (C). A phase contrast MR venogram shows a normal superior sagittal sinus (short arrow) but no flow in the deep venous system (position indicated by long arrow, see also Fig. 57.13E ). (D) 1 week later the patient recovered and a repeat T2 axial image shows almost complete resolution of oedema. The ventricles are also reduced in size. (E). Sagittal T1-weighted image shows high signal thrombus in the internal cerebral vein, vein of Galen and straight sinus (arrows).

 

Slide 17

   Fibrous dysplasia. AP radiograph of the proximal femur showing a well-defined expanded lesion with typical ground-glass matrix mineralization and a thick, sclerotic margin (rind sign). A stress fracture is present in the lateral cortex (arrow).

 

Slide 18

Ependymoma of the fourth ventricle. Sagittal gadolinium-enhanced T1W (A) and axial T2W (B) MRI. A heterogeneously enhancing mass (arrow) fills the lower half of the fourth ventricle and extends through the foramina of Lushka (arrowhead) and Magendie to lie posterior to the medulla oblongata and upper cervical spinal cord, which are compressed from behind. There is obstructive hydrocephalus.

 

Slide 19

   Sacral chordoma. AP radiograph of the sacrum shows a central, lytic destructive lesion (arrows).
CT shows a predominantly lytic mass with small foci of calcification.

 

Slide 20

   Involvement of large bowel in non-Hodgkin's lymphoma. CT showing marked and extensive diffuse, uniform thickening of the wall of the transverse colon (arrow). Mesenteric nodes can also be identified. There is also very marked thickening of the wall of the ascending colon (curved arrow) and caecum.

 

Slide 21

   Hyperparathyroidism. In primary hyperparathyroidism there may be chondrocalcinosis (calcification of cartilage) as illustrated in (A) the knee and (B) the symphysis pubis. Other sites where this may be present are the triradiate ligament of the wrist and the large joints (hip and shoulder). Because of increased osteoclastic activity (C), subperiosteal erosions may be present and are most likely to be evident radiographically along the radial side of the middle phalanges of the 2nd and 3rd fingers. Acro-osteolysis is also present. As there is calcification of the digital artery (metastatic calcification), this is secondary hyperparathyroidism related to chronic renal failure (phosphate retention). Also related to increased osteoclastic resorption there can be (D) cortical ‘tunnelling’ (areas of resorption within the bone cortex) as in the proximal phalanges. (E) Bone cysts (brown tumours, osteitis fibrosa cystica) can occur in any site, seen here in the distal tibia. These cysts are less commonly seen now, as the diagnosis may come to attention in mild or asymptomatic patients who are found to have hypercalcaemia on routine blood testing. In hyperparathyroidism secondary to chronic renal disease there is phosphate retention, increase in the phosphate × calcium product and precipitation on amorphous calcium phosphate in the vessels and in soft tissues, usually around large joints, as seen (F) in the left shoulder.

 

Slide 22

   Meniscal cyst. A cystic structure is seen arising deep to the lateral collateral ligament (arrow), intimately related to the lateral meniscus. An oblique tear is seen through the meniscus confirming that this represents a meniscal cyst.

 

Slide 23

Neuronal heterotopia. Coronal T1-weighted images from a volumetric acquisition; slice thickness is 1.5 mm. (A) Subependymal (nodular) heterotopia (arrowhead), (B) laminar heterotopia (arrowheads).

 

Slide 24

  Cystic hygroma, posterior cervical space. A large water attenuation mass (asterisk) occupies the posterior cervical space on enhanced computed tomography. The left internal jugular vein (arrow) is displaced anteromedially and the sternocleidomastoid muscle (m) is displaced laterally. The muscles (M) of the posterior compartment of the perivertebral space are displaced posteromedially.

 

Slide 25

Progressive multifocal leukoencephalopathy. Axial T2W fast spin-echo image (A), FLAIR (B) and T1W spin-echo image (C). Asymmetrical signal abnormalities in the parieto-occipital white matter of both hemispheres extend to the subcortical U-fibres. There is no mass effect associated with the lesions

 

Slide 26

   Large pericardial effusion. (A) The heart had become rapidly enlarged in this patient who had previously undergone aortic valve replacement. (B) Lateral view demonstrates the pleural fluid lying posteriorly. (C) Unenhanced CT through the level of the valve replacement demonstrates the large pericardial effusion

 

Slide 27

  5 Fluid attenuation structure (asterisk) in the right anterior cardiophrenic angle represents a pericardial cyst.

 

Slide 28

 Adenomyosis. A: Sagittal T2-weighted fast spin-echo (FSE) (4500/108) magnetic resonance image shows enlargement of the uterus and a markedly thickened low signal junctional zone (arrowheads). Multiple foci of high T2 signal are present. B: Axial image using the same technique shows the high T2 foci to be endometrial glands extending into the adenomyoma (arrow). Bilateral high T2 signal ovarian cysts are present.

 

Slide 29

  Cystic adenomatoid malformation. A: Type I lesion, 15-year-old girl, multilocular mass in the right upper lobe containing numerous large cysts. B: Type II malformation, infant girl, a complex mass in the left lower lobe containing multiple small cysts.

 

Slide 30

 Luftsichel sign. (A) A left upper lobe collapse demonstrating paramediastinal lucency (arrow). (B) CT shows interposition of aerated lung between the collapse and the mediastinum (arrow). There is also a large right paratracheal node causing some distortion of the SVC.

 

Slide 31

 8 Osteitis condensans ilii. There is triangular sclerosis along the iliac sides of both SI joints. The sacral sides and SI joints are normal. This is a stress-related phenomenon usually of no clinical significance.

 

Slide 32

 2 Portal vein thrombosis. Contrast-enhanced CT image shows enlargement and lack of enhancement of the main right portal vein (arrow) and peripheral right portal vein branches (arrowheads). Note the transient hepatic attenuation difference (THAD) resulting in increased attenuation of the right hepatic lobe.

 

Slide 33

   Right lower lobe collapse. (A) Frontal view of an example of right lower lobe collapse demonstrating a triangular density which does not obscure the right hemidiaphragm silhouette. (B) The lateral radiograph shows the typical features of increased density of the posterior costophrenic angle and loss of the silhouette of the right diaphragm posteriorly.

 

Slide 34

  Focal nodular hyperplasia. Precontrast CT image (A) shows a large isoattenuating mass (M) in segment IVb of the liver. Arterial phase image (B) demonstrates marked homogeneous enhancement of the mass, which contains a hypoattenuating central scar (arrowhead). During the portal venous phase (C) the mass becomes nearly isoattenuating with the liver parenchyma.

 

Slide 35

  Caroli disease. A: Contrast-enhanced computed tomography of the liver shows numerous non-enhancing cystic structures (arrows) in the hepatic parenchyma. These represent focally dilated biliary ducts. B: Magnified image of the liver shows central foci of high density (arrowheads), which represent vessels surrounded by the dilated ducts, the “central dot” sign.

 

Slide 36

  Pseudomembranous colitis. There is severe low-density mural thickening of the transverse colon. The positive oral contrast material (arrows) is insinuating between grossly edematous colonic folds in an accordion-like fashion.

 

Slide 37

   Retroperitoneal fibrosis (periaortitis). There is a concentric soft tissue abnormality surrounding the aorta with obstruction of the right ureter. Differential diagnosis includes lymphoma and retroperitoneal metastases

 

Slide 38

   Varices. These may be demonstrated on a barium swallow as typical serpiginous filling defects in the lower oesophagus when caused by uphill varices (A). They may be equally well demonstrated at CT examination as enhancing masses either within or as in this case posterior to the lower oesophagus (B). In the latter case note the presence of ascites.

 

Slide 39

   Gastric bezoar. Large mass in stomach – solidified retained ingested fibrous material mixed with air in the patient after a Billroth II anastomosis

 

Slide 40

   Carcinoid. Enhanced CT shows a mesenteric mass with radiating strands toward adjacent bowel loops. An area of dystropic calcification is also evident (arrow).

 

Slide 41

   Haemochromatosis. Unenhanced CT section through the liver of a patient with haemochromatosis showing diffuse increased attenuation of the liver compared with the spleen

 

Slide 42