Unenhanced spiral CT for evaluating acute appendicitis in daily routine. A prospective study.

BACKGROUND/AIMS: The purpose of this study was to define in a routine setting the role of spiral computed tomography in patients with suspected acute appendicitis and to determine the effect of computed tomography on the treatment of such patients.

METHODOLOGY: Appendiceal computed tomography was performed in 120 consecutive patients with acute appendicitis in the differential diagnosis, whose clinical findings were insufficient to perform surgery or to discharge from the hospital. Each scan was obtained in a single breath hold from the lower abdomen to the upper pelvis using a 5-mm collimation and a pitch of 1.6. Computed tomography results were correlated with surgical and pathologic findings at appendectomy or clinical follow-up.

RESULTS: Eighty-eight of the 93 patients with acute appendicitis were correctly diagnosed by computed tomography, 24 of the 27 patients without acute appendicitis were correctly diagnosed by computed tomography (95% sensitivity, 89% specificity). Computed tomography signs of acute appendicitis included fat stranding (100%), enlarged appendix (> 6 mm) (97%), adenopathy (63%), appendicoliths (43%), abscess (10%), and phlegmon (5%).

CONCLUSIONS: The use of spiral computed tomography in patients with equivocal clinical presentation suspected of having acute appendicitis led to a significant improvement in the preoperative diagnosis and a lower negative appendectomy rate. Appendiceal computed tomography is an accurate technique even if performed in the daily routine of scanning.