Hepatobiliary Imaging

Question 1

What is going on in this KUB?

Answer 1

This patient has an appendicolith and associated inflammation. The inflamed fat is pushing on the cecum, creating a divit in the bowel gas.

Question 2

What is going on in this KUB? This patient also has a left renal stone, but ignore that and focus on the other thing.

Answer 2

This is actually a calcified leiomyoma

Uterine fibroids can sometimes calcify on the outside and look similar to stones.

Teratomas in this area might also grow teeth, which appear as masses of calcium.

Question 3

Normal ultrasound view of the CBD and portal vein

Answer 3

Question 4

The five reasons why you may not be able to see the gallbladder on ultrasound

Answer 4

1. Congenitally absent
2. Already removed
3. Ectopic location
4. Non-distended due to inadequate fasting
5. Filled with stones (due to shadowing)

Question 5

What does sludge on gallbladder ultrasound indicate?

Answer 5

Gallbladder stasis

Thus, it is suggestive of obstruction due to cholelithiasis or other etiology

Question 6

What is shown in this gallbladder ultrasound?

Answer 6

Pericholecystic fluid

Question 7

The normal CBD width

Answer 7

< 6 mm up to age 60, then an additional 1 mm per decade thereafter

ie, 7 mm for 70, 8 mm for 80, and so on

Question 8

Non-cholecystitis things that may cause thickened gallbladder and pericholecystc fluid

Answer 8

• Hepatitis
• Diffuse edema of any etiology (hypoalbuminemia, ascites, pancreatitis, etc)
• Adenomyomatosis of the GB
• Peritoneal dialysis
• AIDS

Question 9

Utility of a nuclear medicine hepatobiliary scan

Answer 9

• Diagnose chronic cholecystitis (delayed visualization of gallbladder)
• Diagnose acalculous cholecystitis (if ultrasound is negative)
• Diagnose biliary leak
• Diagnose CBD obstruction (lack of visualization of small bowel)

Question 10

Best study to diagnose appendicitis when the diagnosis is unclear (otherwise you wouldn’t need imaging!)

Answer 10

CT abdomen/pelvis with IV and oral contrast

The contrast is necessary to show the inflammation in the bowel wall.

Oral contrast slightly increases sensitivity on older CT scanners, but new ones don’t need it (so just IV contrast)

Question 11

Normal appendix on ultrasound

Answer 11

If the wall is thickened > 6 mm OR an appendicolith is visualized in the appropriate clinical context, this is diagnostic of appendicitis

Remember that US is the study of choice for diagnosis in pregnant patients and children.

Question 12

Imaging study of choice in acute cholangitis

Answer 12

Ultrasound

Question 13

When might you do an MRCP first to confirm the diagnosis of choledocolithiasis rather than proceeding straight to an ERCP?

Answer 13

• If the patient has a history of pancreatitis (to avoid unnecessary ERCP pancreatitis)
• If the patient has significant anesthetic risks (COPD, CAD, difficult airway, etc)