Diverticulosis / Diverticulitis

What is diverticulosis and what is diverticulitis?

• Diverticulosis refers to blind pouches leading off the alimentary tract.
• Diverticulitis is a condition that occurs when diverticula become infected and inflamed.

Acute diverticulitis occurs when a section of colon reveals acute inflammation (hyperemia, swelling) of the serosa and pericolic fat.

A section of colon reveals numerous diverticula which protrude from the edge of the taenia coli (*). The colon is cut in cross section revealing the diverticuli (contain feces) and the empty colonic lumen.

What is the mode of clinical presentation of diverticulosis?

• Most of the time they are discovered incidentally.
• Clinical presentation changes once there is a complication.

What are the potential complications of divericula?

• Inflammation (diverticulitis)
• Chronic blood loss/rarely acute hemorrhage
• Abdominal discomfort/constipation/diarrhea

What are the complications of diverticulitis?

• Abscess
• Bleeding
• Fistula
• Obstruction
• Perforation
•  

What are the imaging studies to detect findings of diverticulosis?

• Lower GI
• CT

Diverticula

Diverticula CT: Arrowheads point to multiple diverticula arising from the rectosigmoid.

What is the imaging procedure of choice to demonstrate diverticulitis?

• CT:
  • CT is the imaging procedure of choice to evaluate diverticular disease, as it can show many aspects of disease that are not recognizable by other studies.
  • For inflammation or abscess, helical CT with colonic contrast has a sensitivity and specificity of 97 and 100%.
  • CT scan can assess complications better.
• Ultrasound:
  • If the target diagnosis is an abscess, then ultrasound has a sensitivity and specificity of 97 and 98%.
• US can be sub optimal because of intestinal gas.
• It is operator dependent.
• Contrast enema can demonstrate divericulosis and diverticulitis, but is rarely done at present.

What are the imaging findings of diverticulitis?

• US: Abnormal wall thickening of more than 4 mm involving a segment 5 cm or longer at the point of maximal tenderness.
• CT:
  • Diverticula
  • Narrowed lumen
  • Thickened bowel wall
  • Fascial inflammatory infiltration
  • Complications
    • Perforation: Free air in the peritoneum
    • Abscess

Diverticulitis

Diverticulitis with Abscess Findings: White arrowheads: Diverticula White arrow: Narrowed lumen Black arrow: Perforation with intramural abscess