Diagnostic performance of multidetector CT for acute cholangitis: evaluation of a CT scoring method

Abstract

Objective: The aim of this study was to retrospectively assess the diagnostic performance of multidetector CT (MDCT) for the diagnosis of acute cholangitis using a new scoring method. Methods: Of 80 patients with suspected biliary disease who underwent biphasic CT and endoscopic retrograde cholangiography, 39 were diagnosed as having acute cholangitis (Group 1) and 41 patients were classified as suspected biliary disease (Group 2). 100 age-matched patients without evidence of biliary disease were selected randomly as a control group (Group 3). Each patient's axial scan was scored by two independent radiologists for the extent of transient hepatic attenuation difference, the presence of biliary dilatation and identification of a biliary obstructive lesion. The difference in the scores among the three groups was evaluated and the optimal cut-off score for the diagnosis of acute cholangitis was determined. Interobserver agreement was also evaluated. Results: The total scores (mean +/- standard deviation) for Groups 1, 2 and 3 were 7.0 +/- 2.0, 4.4 +/- 2.4 and 0.9 +/- 1.2, respectively, for Reviewer 1 and 7.2 +/- 2.7 and 0.7 +/- 1.1, respectively, for Reviewer 2. Significant differences were found for the subscores and the total scores among the three groups (p<0.001). Using a cut-off score of >= 5, the sensitivity and specificity for diagnosing acute cholangitis were 84.6% and 83.7%, respectively, for Reviewer 1 and 89.7% and 83.7%, respectively, for Reviewer 2. Agreement for the subscores between readers was good to excellent (kappa=50.74-0.86). Conclusion: Based on dynamic MDCT and the described CT scoring method, the diagnosis of acute choangitis can be made with high sensitivity and specificity.