[anatomy&imaging][module B]

Question 1

Answer 1

AxialCT: • Gross thickening of oesophagus (should be very thin) anterior to the descending aorta. • Other visible structures = liver, IVC, stomach (ant to diaphragm)

Question 2

Answer 2

Demonstrates the top and bottom extent of the thickened portion of the oesophagus (behind the heart). The edges are “shouldered”.

Question 3

Answer 3

Demonstrates dilatation of the oesophagus above the lesion (the lesion is causing obstruction, so air collects behind it).

Question 4

Answer 4

The liver surface is irregular anteriorly (not smooth), in keeping with cirrhosis. • Ascites is seen in the abdomen (anterior to liver) due to liver failure. The umbilical vein has reopened (the origin from the left portal vein is arrowed) – this closes after birth but reopens in portal hypertension (portosystemic collaterals)

Question 5

Answer 5

Irreg liver and ascites • Reopened umbilical vein (white arrow) seen in the falciform ligament • Multiple new collaterals around gastric fundus (dashed arrow) , These collaterals form the caput medusae sign at the umbilicus = portal hypertension

Question 6

Answer 6

Rounded thickened bowel in RIF containing a crescent of fat (arrowed). This is actually the mesenteric fat associated with the telescoping bowel. o i.e. mesenteric fat should only lie outside the bowel lumen, but here it lies within as it has been pulled in by the telescoping bowel (see pic below).

Question 7

Answer 7

This image shows the entry of the fat (i.e. the point of intussusception very well.

Question 8

Answer 8

USS shows a thickened loop of bowel (grey arrow), containing a 2nd loop of bowel within (dashed arrow) and a crescent of fat (bright, solid white arrow).

Question 9

Answer 9

Discuss the difference in the 2 films. 1) One is thickening due to active colitis. 2) The second shows thickening and colonic dilatation – this dilatation is rapid and associated within deterioration / sepsis / perforation in the patient. This should be spotted early and managed aggressively, often with surgery.

The term thumbprinting refers to the wall-thickening which mimics multiple thumbprints in its undulation (arrowed).

Question 10

Answer 10

Thickening of the haustra (arrowed, aka thumbprinting), and dilatation of the transverse, descending and proximal sigmoid colon.

This is toxic megacolon

Question 11

Answer 11

Free air under the diaphragm = bowel perforation o Note the air is crescentic which is in keeping with free air. o If the air had a rounded appearance, it cis more likely within bowel (e.g. stomach fundal gas).

Question 12

Answer 12

High density in the CBS within the pancreas (arrowed) = gallstone dropped into CBD fropm gallbladder. • Discuss biliary and pancreatic duct anatomy – how can a gallstone obstruct pancreatic duct?

With that high an amylase, pancreatitis has to be top. o Mnemonic for causes of pancreatitis – GET SMASHED. o In this case due to gallstones.

Question 13

Answer 13

Inflammation / fat necrosis (low density, arrowed) around pancreatic body into lesser sac

Question 14

Answer 14

The medial aspect of the uncinate process does not enhance well – likely pancreatic necrosis (a poor prognostic factor in pancreatitis)

Question 15

Answer 15

The inflammation has spread to surround the transverse colon (the colon is arrowed). This can lead to the colon cut-off sign seen on Xrays, and occasionally the fat necrosis can damage the bowel.

Question 16

Answer 16

Right hip normal (dimple in femoral head = fovea). • Left hip - reduced joint space, flattening, subchondral sclerosis and cysts. Mild lateral osteophyte formation.

Salter Harris fractures involve the growth plate.

Question 17

Answer 17

Mild erosions at the MCP joints of both thumbs (1st MCPs) • Subluxation and Boutonniere’s deformity of the 1st MCP joints. • Appearances are in keeping with RA.

Question 18

Answer 18

The SI joints are not visible (fused) • The lateral aspects of the vertebral bodies appear fused o This is because the outer margin of the annulus fibrosis (of the intervertebral disc) is calcified. o This appearance is known as a bamboo-spine as it mimics the unbulations of a stick of bamboo. • The spinous processes appear fused o This is because the interspinous and spraspinous ligaments are calcified.

Question 19

Answer 19

Annulus fibrosis calcification

also sacroiliac joint fusion

Question 20

Answer 20

But on the sagittal reformat, you can also see calcification of the anterior longitudinal ligament: • Anterior longitudinal ligamnent calcn (solid arrow) • Interspinous / supraspinous ligament calcification (dashed arrow)

Question 21

Answer 21

Calcification of lateral aspect of supraspinatus tendon (arrow).

Question 22

Answer 22

Full thickness supraspinatus tendon tear (arrow) • Fluid comunicates between glenohumeral joint and subacromial bursa through the gap.

Question 23

Answer 23

Gap between biceps tendon (solid arrow) and infraspinatus tendon (dashed arrow) o The torn suprasinatus tendon is missing (should occupy this gap)

Question 24

Answer 24

The infraspinatus muscle (arrowed) shows fatty atrophy (secondary to the tear).

Question 25

Answer 25

Normal lateral meniscus (triangles anteriorly and posteriorly, arrowed)

Question 26

Answer 26

Defect (bright area) in the posterior aspect of the medial meniscus (arrowed). • Knee effusion anteriorly

Question 27

Answer 27

This image is more medial in the joint. • Posterior cruciate ligament (PCL) seen superiorly – dashed arrow. • Flipped fragment of the medial meniscus is seen inferiorly (solid arrow), mimicking a second PCL - aka “double PCL sign”. This represents a bucket-handle tear of the meniscus. • Anterior effusion.

Question 28

Answer 28

Defect (bright area) in the medial meniscus (arrowed). • Lateral meniscus normal

Question 29

Answer 29

Again the flipped fragment of the medial meniscus (the “bucket handle”, solid arrow) is seen inferior to the PCL (dashed arrow)