Can negative appendectomy rate be decreased by using spiral computed tomography without contrast material?

Approximately 15-20% of error in the diagnosis of acute appendicitis argues for new diagnostic methods. In recent years it has been proposed that Computed Tomography be used in the diagnosis of acute appendicitis with high sensitivity and specificity. In our study, the effect of Computed Tomography on the diagnosis of acute appendicitis and on negative appendectomy was investigated on patients with suspected acute appendicitis. In the last 18 months, spiral Computed Tomography without contrast material has been used for 65 patients. The history, physical findings, laboratory results and Computed Tomography images of patients were compared and the final decision to operate was always made by an attending surgeon. The results of Computed Tomography have been correlated with the reports of pathology and operation findings. Other patients who have not been operated on have been followed up clinically. Correlating Computed Tomography results with operation findings revealed; 42 true positive, 3 false positive, 17 true negative and 3 false negative results. The sensitivity and specificity of CT have been found to be 93.3% and 85% respectively. Forty-eight out of 65 patients have been operated on for acute appendicitis and the negative appendectomy rate has been calculated as 6.25%. As a consequence, it was thought that in the diagnosis of acute appendicitis the use of Computed Tomography could decrease the negative appendectomy rate when used together with clinical follow-up.