Intravenous Contrast-enhanced Computed Tomography in the Diagnosis of Acute Appendicitis

This study evaluated the usefulness of routine, nonfocused intravenous contrast-enhanced computed tomography (CT) in diagnosing acute appendicitis. Also evaluated was the diagnostic value of several findings that were clinically associated with acute appendicitis. Although a number of studies have shown various techniques using CT to be accurate in the diagnosis of acute appendicitis, few studies have focused on CT with using only intravenous contrast material. Computed tomography scan criteria for acute appendicitis have been established chiefly on the basis of appendiceal findings. We, on the other hand, have often observed the following associated conditions during appendectomy: ascites, paresis of the intestine, or thickening of adjacent tissues. In this study, we reviewed the intravenous contrast-enhanced CT scans of 78 patients who had been diagnosed as having acute appendicitis and had subsequently undergone surgery. We also compared the CT scans with patients’ surgical and histological findings. As a way of evaluating clinical ancillary signs, we identified and analyzed individual CT findings that included abnormal appendix, calcified appendicolith, ascites, dilated intestine, and cecal wall thickening. The sensitivity, specificity, and accuracy of intravenous contrast-enhanced CT in surgical cases were found to be 91.9%, 87.5%, and 91.0%, respectively. Individual findings except for abnormal appendix were not significantly common among patients who had acute appendicitis. However, more positive findings were observed in patients who had appendicitis than in those who had normal appendixes. Intravenous contrast-enhanced CT scan is a useful technique in the diagnosis of acute appendicitis. The plurality of ancillary signs in CT scans also appears to be a helpful indicator in the diagnosis of acute appendicitis.