[Adult intestinal intussusception: comparison between CT features and surgical findings].

Purpose: To report our experience in the use of CT in the evaluation of adult intestinal intussusception. A correlation between radiologic findings and surgery was attempted in order to verify our diagnostic hypothesis.

Material And Methods: Intestinal intussusception was diagnosed by CT between September 1993 and December 2000 in 10 patients (6 men and 4 women, age range 18-82 years). For 9/10 patients the diagnosis was confirmed by surgery; in one patient the condition resolved spontaneously as confirmed by a follow-up CT performed 24 hours after the first. Six patients were studied by a third generation CT and four by a helical CT unit. Five patients were administered iodinated oral contrast medium and in seven i.v. iodinated contrast medium. Diagnosis was hypothesized at CT on the basis of the following aspects: target, sausage, and pseudokidney.

Results: Surgery confirmed the CT diagnosis of intussusception in 9/10 patients; in the patient with transient intussusception a spontaneous resolution was confirmed at follow up CT after 24 h. In the 10 patients studied the following CT aspects were observed in the bowel involved by intussusception: a target aspect in 4 patients; a sausage aspect in 4 patients; in one of them a peritoneal effusion was also present; a pseudokidney aspect was observed in 2 patients, with a long tract intussusception and peritoneal adipose tissue; in both a hyperdensity of the peritoneal adipose tissue and enlarged vessels, that were herniated within the lumen of the bowel, were recognized. At surgey the causes of intestinal intussusception were: malignant tumors of the colon (4 cases), hamartomatous polyps of the small bowel (2 cases), mixoid fibrolipoma of the colon (one case), leiomyoma of the distal ileum (one case). In one patient no cause could be identified at CT, but the condition was found to co-exist with acute appendicitis at surgery.

Conclusions: CT is an accurate technique in the evaluation of intestinal intussusception in adults. It allows to identify the condition, its site, and sometimes the type of the lesion causing the intussusception, and any vascular alteration, thus playing an important role in establishing the most appropriate therapeutic strategy.