Imaging description

Meckel's diverticulum, named after the German anatomist Johann Friedrich Meckel who first described it in 1809, is a blind sac arising from the antimesenteric border of distal ileum approximately 40–100 cm upstream from the ileocecal junction that occurs as a congenital anomaly in about 2% of the population [1,2]. The diverticulum is a developmental remnant due to incomplete regression of the vitelline (or omphalomesenteric) duct that connects the midgut to the yolk sac during early fetal life. The diverticulum can become inflamed and present as an acute abdomen. Historically, a preoperative diagnosis of complicated Meckel's diverticulum has only been made in 6 to 10% of cases [3, 4], but with the emergence of CT the diagnosis of Meckel's diverticulitis can be made with high accuracy. At CT, an inflamed Meckel's diverticulum appears as a blind-ending pouch of variable size with mural thickening and surrounding mesenteric inflammation (Figures 61.1 and 61.2) [5]. That is, an inflamed Meckel's diverticulum resembles an inflamed appendix, except that it is attached to the distal ileum rather than the cecum.

Importance

The total lifetime complication rate of a Meckel's diverticulum is approximately 4% [6], and common symptomatic complications include inflammation, bleeding, obstruction, and inversion with intussusception. Inflammation may result from obstruction with infection (like acute appendicitis), torsion, or peptic inflammation secondary to ectopic gastric mucosa within the diverticulum [3].