9) CT of the GI Tract

Question 1

CT of the GI tract

Answer 1

• Demonstrates conditions that alter the thickness of the bowel wall (which plain radiography cannot)
• Can also show conditions that produce changes adjacent to the bowel wall

Question 2

CT of the GI tract looks for

Answer 2

• Bowel wall thickening
• Diverticular disease
• Appendicitis
• Bowel obstruction
• Ischemia

Question 3

Chron’s Disease CT findings

Answer 3

• Marked thickening of the wall of the terminal ileum on bot axial and coronal slices

Question 4

Diverticulosis

Answer 4

• Common large bowel condition
• Results from herniation of portions of the mucosal and submucosal layers of the colonic wall through the muscular layer

Question 5

Diverticulitis

Answer 5

• Occurs when fecal material becomes trapped within a diverticulum, resulting in perforation and abscess formation

Question 6

Diverticula appear on CT scan as

Answer 6

• Air-filled outpouchings

Question 7

CT of appendicitis key conepts

Answer 7

• Diagnostic imaging is recommended for all patients suspected of appendicitis
• Plain films, CT, and ultrasound can show pathologic changes in the appendix, but CT shows them best
• CT can determine not only whether appendicitis is present, but also whether perforation or abscess formation have occurred

Question 8

CT of bowel obstruction key concepts

Answer 8

• Plain films may show only the signs of bowel obstruction (e.g. air fluid levels)
• CT may demonstrate the cause of the obstruction (e.g. neoplasm, intussussception, adhesions)
• Most common cause of SBO is from adhesions due to prior surgery

Question 9

CT of bowel ischemia key concepts

Answer 9

• Interruption of blood flow to the bowel can result in bowel ischemia and necrosis
• CT can identify bowel infarction by showing the presence of gas within the bowel wall, and portal venous system