CT-colonography in the follow-up of acute diverticulitis: patient acceptance and diagnostic accuracy

Objective. The aim of this study was to assess CT-colonography (CTC) in the follow-up of diverticulitis regarding patient acceptance and diagnostic accuracy for diverticular disease, adenomas and cancer, with colonoscopy as a reference standard. Methods. A prospective comparative study where half of the patients underwent colonoscopy first, followed immediately by CTC. The other half had the examinations in the reverse order. Patient experiences and findings were registered after every examination, blinded to the examiner. Results. Of a total of 110 consecutive patients, 108 were included in the study, with a median age of 56 years (range 27-84). The success rate was 91% for colonoscopy and 86% for CTC. Examination time was 25 mm for both methods. The mean time for CTC evaluation was 20 mm. Eighty-three per cent of the patients received sedation during colonoscopy. Despite this, patients experienced colonoscopy as more painful (p < 0.001) and uncomfortable (p < 0.001). Diverticulosis and polyps were detected in 94% and 20% with colonoscopy and in 94% and 29% with CTC, respectively. Sensitivity and specificity for CTC in the detection of diverticulosis was 99% and 67%, with a good agreement (kappa = 0.71). Regarding detection of polyps, the sensitivity and specificity were 47% and 75%, with a poor agreement (kappa = 0.17). No cancer was found. Conclusion. CTC was less painful and unpleasant and can be used for colonic investigation in the follow-up of diverticulitis. CTC detected diverticulosis with good accuracy while the detection accuracy of small polyps was poor. CTC is a viable alternative, especially in case of incomplete colonoscopy or in a situation with limited colonoscopy resources.