Small bowel

Question 1

Duodenum anatomy

1. Does it have a mesentery?
2. Which portion is intraperitoneal?
   
   1. Which are retroperitoneal?
3. What delineates the four parts?

Answer 1

1. Nope.
2. Segment 1: duodenal bulb.
3. Segments 2-4 are retroperitoneal.
4. Segment 1: bulb; it’s intraperitoneal.
   
   1. Segment 2: descending
   2. Segment 3: horizontal, ends at the SMA impression.
   3. Segment 4: ascending, ending at the ligament of Treitz, which holds the duodenum up at the duodenojejunal flexure.

Question 2

SB follow-through: trademark features

1. What is this SB pattern?
2. What’s the Dx?
3. In who is this seen?

Answer 2

1. Hidebound bowel: narrow separation of normal folds w/mild bowel dilation.
2. Scleroderma.

Question 3

SB follow-through: trademark features

1. What are these SB pattern?
2. What’s the Dx?

Answer 3

1. 1st: moulage sign (tube of wax); complete loss of jejunal folds.
   
   1. 2nd: fold reversal: jejunum loses folds so looks like the normal ileum; ileum gains folds (in the RLQ) to look like jejunum.
2. Celiac disease.

Question 4

SB follow-through: trademark features

1. What is this SB pattern?
2. What’s the Dx?

Answer 4

1. Thread-like defect in the barium column.
2. ascariasis: round worm.
   3.

Question 5

SB follow-through: trademark features

1. What is this SB pattern?
2. What’s the Dx?
3. In who is this seen?

Answer 5

1. Ribbon bowel.
   
   1. From SB thickening.
2. Graft vs. host disease.
3. Pts post stem cell/bone marrow transplant.

Question 6

Duodenal trauma:

1. 3 classic findings.

Answer 6

1. Free gas: less than with an ulcer.
2. Periduodenal free fluid.
3. Potential duodenal wall thickening.

Question 7

Duodenal intramural hematoma:

1. Which portions are most at risk?
2. What other underlying pathology can cause this?
3. Which pt group is most susceptible to this?

Answer 7

1. Segments 2 & 3.
2. Anticoagulation
3. Kids.

Question 8

Brunner gland hyperplasia:

1. Path?
2. What segments affected?
3. What’s the appearance?

Answer 8

1. Disproportionate growth of Brunner glands int he duodenum from hyperacidity.
   
   1. Hyperplasia begins at the pylorus & extends distally to duodenal segments 2/3.
2. Ix: multiple nodular filling defects, typically in the 1st portion of the duodenum.

Question 9

Small bowel trauma

1. Most common location for SB injury w/blunt trauma?
2. Which CT trauma finding is a strong predictor of significant mesenteric and/or bowel injury?

Answer 9

1. Duodenum & jejunum: they’re closest to the spine.
2. Seatbelt hematoma + Chance fracture.

Question 10

1. Classic finding name?
2. Dx?

Answer 10

1. balloons on a string
2. closed loop SBO
   
   1. Note the blurred margins b/w loops
   2. Fluid-distended SB.

Question 11

This is the small bowel in a pt w/NHL. What is the name of this sign and what does it represent?

Answer 11

• Pseudokidney sign.
  
  • Hypoechoic, concentric bowel wall thickening & a central echogenic area w/dirty shadowing corresponding to the air-filled lumen.
  • The peripheral hypoechoic thickened wall simulated the renal cortex.