Suspected appendicitis. Impact of enhanced helical CT. Prospective study in 100 patients.

Aim of the study: To assess the diagnosis accuracy of helical computed tomo graphy (CT) in patients with suspected appendicitis. Patients and methods: This prospective study included 100 consecutive patie nts hospitalized for suspected appendicitis. There were 57 men and 43 women with a median age of 30 years (range: 17-91). An enhanced helical CT was p erformed at admission, without digestive opacification. Four criteria were interpreted as positive signs for appendicitis: appendix enlarged greater t han or equal to 7 mm, right lower quadrant inflammation, stercorolith, and peri-appendicular collection. The patient was managed by the surgeon withou t knowing the result of CT. The final diagnosis was made pathologically. Results: Eighty-one patients were operated on laparoscopically for suspecte d appendicitis. Intraoperative diagnosis was corrected in three cases and 7 8 appendectomies were performed (73 histological appendicitis, six normal a ppendix). Final diagnosis was a medical disease in 19 patients. The finding s of 67 CT were interpreted as positive (63 true positive and four false po sitive) and the findings of 33 CT were interpreted as negative (24 true neg ative, nine false negative). Sensitivity was 87%, specificity was 86%, posi tive predictive value was 94%, and negative predictive value was 73%. If th e nine false negative cases with minimal lesions at pathological examinatio n were considered as true negative, the rates would be 100%, 89%, 94%, 100% , respectively. Conclusion: Enhanced helical CT is a good imaging diagnostic tool for suspe cted appendicitis. It may reduce the number of patients admitted for observ ation and decrease the rate of negative appendectomy. (C) 2001 Editions sci entifiques et medicales Elsevier SAS.