Lipoma. (A) On mammography, a lipoma may be seen as a well-defined mass of fat density, contained within a thin capsule. (B) On ultrasound, a well-defined hyperechoic lesion characteristic of a lipoma is seen.
Skull fractures. (A) Lateral skull radiograph demonstrating complex, diastatic temporoparietal skull fractures associated with pneumocephalus. A linear occipital component is also present
Duct ectasia. (A) Broken needle appearance, typical of duct ectasia. (B) Sometimes thicker, more localized calcifications can be seen, giving a ‘lead-pipe’ appearance
Ischaemic colitis. A thick-walled oedematous descending colon outlined by gas. Slightly distended colon from caecum to splenic flexure, but with normal haustra and no evidence of abnormal mucosa.
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.
Myositis ossificans. (A) Axial CT at presentation showing early peripheral mineralization. (B) Six weeks later there has been maturation with well-organized peripheral ossification.
Alobar holoprosencephaly CT brain of this infant shows that the cerebral hemispheres have failed to form and there is no interhemispheric fissure or corpus callosum. Instead there is a thin pancake of cerebral tissue crossing the midline anteriorly (arrowhead) and a single holoventricle continuous with a large dorsal cyst. The midbrain and deep grey structures are fused into a single indiscriminate mass (arrow).
Septo-optic dysplasia in a child with HESX1 gene mutation. (A) The septum pellucidum is absent and the frontal horns have a typical box-like configuration. (B) The posterior pituitary gland is ectopic (arrow). (C,D) The right optic nerve is small (arrows).
Low-grade liposarcoma. Sagittal T1-weighted MR image of the thigh showing a heterogeneous mass. The cephalic portion is hyperintense, typical of simple lipoma, whereas the caudal component is isointense with muscle, much more suggestive of sarcoma
(A) Gastric emphysema on abdominal radiograph in a patient with ischaemic gastritis after extensive abdominal surgery. (B) CT of patient with infectious, emphysematous gastritis.
Ellis–van Creveld syndrome. Partial duplication of the fifth metacarpals (postaxial polydactyly), deformed hamate and short middle and terminal phalanges with cone-shaped epiphyses
Diffuse hemangioendotheliomatosis in a neonate. A: Arterial phase computed tomography (CT) image obtained 12 seconds after the start of contrast administration demonstrates multiple high-attenuation lesions in the liver. B: Portal venous phase CT scan obtained 50 seconds after injection of contrast medium demonstrates nearly complete washout of the lesions.
Chronic renal failure (two different cases). (A) PA hand radiograph showing the florid features of secondary hyperparathyroidism including terminal phalangeal resorption, soft tissue calcification, subperiosteal resorption, vascular calcification and osteopenia. (B) Tumoral calcinosis with heavy periarticular calcification
Chondrocalcinosis of the menisci. Ossification adjacent to the medial femoral condyle indicates old medial collateral ligament injury (Pellegrini–Stieda lesion).
Malrotation. Contrast-enhanced computed tomography shows reversal of the normal orientation of the superior mesenteric vessels, with the artery (black arrow) lying to the right of the vein (white arrow).
Lisfranc injury. A: Axial image through the upper midfoot demonstrates lateral subluxation of the first and second metatarsals relative to the medial and middle cuneiforms. B: Farther inferiorly, the fourth and fifth metatarsals are also laterally subluxed relative to the cuboid.
Longitudinal (A) and transverse (B) US views of organizing scrotal haematoma following trauma. The adjacent testis is compressed but otherwise normal. A septated hydrocele may present a similar appearance
Osteochondromas: chest. A: Axial CT of the right chest shows a large osteochondroma projecting anteriorly from the scapular body. Note marrow continuity into the bony excrescence. A cartilage cap is not well seen. The patient noticed a popping sensation with scapulothoracic motion. B: Axial CT of the left chest in the same patient shows a pedunculated osteochondroma projecting into the left lower lung. A cartilaginous cap is noted.
Retroperitoneal teratoma. Contrast-enhanced computed tomography scan demonstrates a large predominantly fluid-filled mass containing areas of fat and calcification
Grade I urethral injury. Retrograde urethrogram shows a stretched but intact urethra with elevation of the bladder base. Marked diastasis of the pubic symphysis is evident.
Mesenteric venous thrombosis. Enhanced CT, coronal reformation image shows circumferential thickening of distended jejunal loops (white arrows) and haziness of the adjacent mesentery. Nonopacification of superior mesenteric and jejunal branches is noted (black arrows). Ascites is also present.
Conventional chondrosarcoma pelvis. A: AP radiograph shows the large soft tissue mass with cartilaginous-type calcification/ossification. B and C: Axial CT images again demonstrate the circumferential mass, as well as the radiolucent replaced marrow of the underlying hemipelvis
Callosal agenesis. (A) Axial T2-weighted MRI shows separated ventricles with parallel orientation. The superior part of the third ventricle is just seen. (B) Sagittal T1-weighted MRI through the midline confirms callosal agenesis. There is no cingulate sulcus and the vertically oriented cerebral sulci extend right down to the third ventricle. This finding is associated with other midline anomalies such as a fronto-ethmoidal cephalocele (arrow), seen also on the axial T2-weighted MRI (arrow, C). (D) The optic chiasm is absent.
Osteopetrosis. (A) Increased bone density with relative radiolucent bands at the metaphyses of the humeri and also in the iliac wings. (B) Increased bone density with deformity and abnormal modelling. There is a pronounced ‘bone-in-a-bone’ appearance. (C) Bands of increased bone density, especially well seen at the vertebral end plates. (D) In another patient, bands of increased sclerosis are seen in the relatively mild autosomal dominant form.
Pseudomyxoma peritonei. Coronal T2-weighted magnetic resonance image demonstrates multiple confluent high signal intensity perisplenic cystic masses (arrows) that cause scalloping of the splenic margin. Also note the perihepatic and subhepatic tumor implants (arrowheads).
Extensive bilateral cerebral hemisphere polymicrogyria. Virtually no normal cortex is seen. At first glance the cortex appears thickened but closer inspection reveals an overconvoluted gyral pattern and a ‘lumpy bumpy’ grey–white matter interface (including regions marked by white arrows). The Sylvian fissure is abnormally oriented with a parietal cleft that extends posteriorly (black arrow).
Lower lobe atelectasis. Postcontrast computed tomography demonstrates marked enhancement of the collapsed left lower lobe (arrowheads) and posterior basal segment of the right lower lobe (arrow) in a postabdominal surgery patient suspected of having pulmonary embolism.
Calcified bronchial carcinoids. A: Computed tomography shows a mainly extraluminal mass arising from apical bronchus (arrow) of the right upper lobe. B: In another patient, computed tomography demonstrates a large mainly extraluminal mass arising from the right lower lobe bronchus (arrow).