Purpose: To evaluate the diagnostic accuracy of thin collimated unenhanced spiral-CT in patients with clinically suspected acute appendicitis and to determine the impact on patient management and overall costs.
Method: Unenhanced focussed appendiceal spiral-CT was performed in 56 patients (23 women and 33 men) with clinically suspected acute appendicitis. Scans were obtained from the L4 level to the symphysis pubis using 5 mm collimation, 7.5 mm table feed (pitch 1.5) and 4 mm increment without i.v., oral, or rectal contrast material. Prospective diagnoses based on CT findings were compared with surgical (and histopathological) results and clinical follow-up. The effect of spiral-CT on patient management and clinical resources was assessed.
Results: 29 patients (10 women and 19 men) underwent appendectomy. Unenhanced spiral-CT was an accurate imaging technique for the initial examination of patients with suspected acute appendicitis with a sensitivity of 95.4% and a specificity 100%, an accuracy of 98.2%, a positive predictive value of 100%, and a negative predictive value of 97.1%. In 27 patients with no evidence of acute appendicitis, an alternative diagnosis could be made in 24 patients by unenhanced spiral-CT.
Conclusion: Unenhanced spiral-CT is an accurate test to diagnose or to exclude acute appendicitis. Routine appendiceal spiral-CT can improve medical care and reduce the overall costs for patients suspected of having acute appendicitis.