Hepatobiliary scintigraphy is superior to abdominal ultrasonography in suspected acute cholecystitis

Background. Hepatobiliary scintigraphy is a very accurate test in the diagnosis of acute cholecystitis. However ultrasonography is extensively used for the diagnosis of this disease. In this study we directly compare the diagnostic accuracy of these techniques for acute cholecystitis. Materials and Methods. The diagnostic accuracy of scintigraphy and ultrasonography was evaluated in 107 consecutive patients with suspected acute cholecystitis who underwent both imaging nodalities within one day. The incremental diagnostic value of each modality was determined. Results. The sensitivity, specificity positive and negative predictive values, and accuracy for the diagnosis of acute cholecystitis in the entire cohort were superior for scintigraphy compared with ultrasonography. The accuracy wets 92 % for scintigraphy and 77 % for ultrasonography. Similarly, if only surgically treated patients were considered, the accuracy of scintigraphy was 91 % versus 61 % for ultrasonography. The diagnostic value of scintigraphy for the entire cohort was significantly superior to ultrasonography (global, chi 2 = 58.1 vs 9.7, respectively); the addition of the information derived from the latter did not futher improve the diagnostic value of scintigraphy (global, chi 2 = 58.2). Conclusions. Hepatobiliary scintigraphy has superior diagnostic accuracy for acute cholecystitis compared with ultrasonography. The addition of ultrasonography does not further improve the diagnostic accuracy of scintigraphy alone.