[US and CT findings in complicated Meckel diverticulum]

Meckel s diverticulum is the most common congenital abnormality of the small bowel. It may be silent or symptomatic when complicated by hemorrage, intestinal occlusion, diverticulitis and umbilical fistulas. Radiologic diagnosis is often difficult because abdominal plain radiography and ultrasound are not sufficiently specific; CT is most accurate in differential diagnosis. MATERIAL AND METHODS. 11 patients (age 5-69 ys) were studied. Clinical symptoms included acute abdomen (4 pts), intestinal occlusion (3 pts), abdominal pain (4 pts), fever (5 pts). Radiological studies were abdominal plain radiography (8 pts), ultrasound (5 pts), CT (9 pts).

Abdominal plain radiography depicted signs of intestinal occlusion (4 pts) and perforation (1 pts); in 4 pts the signs were non diagnostic. Ultrasound showed an abscess in the pelvis (2 pts), dilatation and wall-thickening of an intestinal loop (2 pts), intestinal invagination (1 pts); it was not diagnostic in 3 pts. CT was not diagnostic in 3 pts; in 2 pts it showed an abscessual fluid collection in the pelvis, adherent to intestinal loops, with flogosis of the perivisceral fat; in 1 pt it revealed perforation; in 4 cases it was specific showing inversion of the diverticulum in an intestinal loop (2 pts) or a tubular fluid-filled structure, with thickened walls and contrast enhancement, which was interpreted as a inflammatory diverticulum (2 pts).

Our series confirms the difficulty of diagnosing Meckel s diverticulum in an acute setting. Abdominal plain radiography only allowed to diagnose intestinal occlusion or perforation. Ultrasound revealed abscessual collections in the pelvis, fluid distention of the diverticulum, segmental thickening of the intestinal walls and invagination. CT proved to be more specific showing signs suggestive of correct diagnosis in 6 pts. In particular, evidence of an intraluminal prolonged mass with central area of fat density and peripherral collar was considered suggestive of intraluminal invagination of Meckel s diverticulum. Another diagnostic sign is the evidence of a tubular fluid-filled structure, with thickened, enhanced walls. In 2 cases CT showed an abscessual collection with gas-fluid level (complication of perforation) confirming the need for surgery.

Meckel s diverticulum is a not uncommon condition that in some cases is complicated, resulting in acute abdomen. Preoperative radiological diagnosis can be suspected in the presence of suggestive signs, more often depicted by CT.