CT evaluation of appendicitis and diverticulitis. Part II: Diverticulitis

CT has become the primary imaging modality for evaluation of possible diverticulitis. In studies of patients taken to surgery for suspected diverticulitis without first undergoing CT, 25-33% of resected specimens show no inflammation. The overall accuracy of CT in establishing or excluding the diagnosis is between 84 and 99%. In patients without diverticulitis, an alternative diagnosis is seen in 50-58% of cases. The appearance of carcinoma with perforation and diverticulitis may be the same, and, as a result, the degree of certainty in the diagnosis should be stated. Techniques include use of either oral and intravenous contrast or rectally administered contrast. No case of colonic perforation due to rectally administered water-soluble contrast for CT has been reported, although there have been cases of perforation using barium and fluoroscopy. All techniques scan the entire abdomen and pelvis since there are frequent alternative diagnoses seen beyond the area of initial pain.