Comparison of Ultrasonography and Computed Tomography to Evaluate the Causes of Biliary Obstruction

Abstract

Objective: To observe the role of computed tomographic (CT) scan and ultrasonography (USG) examination to evaluate the causes of biliary obstruction. Materials and methods: This cross-sectional study was conducted in a total of 57 patients clinically suspected of obstructive jaundice. Results: The highest incidence of biliary obstruction was found in the age group between 40 and 49 years and the mean (±SE) age of the patients was 48.4 ± 1.6 years. Serum bilirubin and serum alkaline phosphatase were high in all patients. For evaluation of pancreatic mass, USG found true positive in 13 with no false positive, false negative 2 and true negative 42 cases. Similarly, CT scan found true positive in 15 and no false positive, no false negative and true negative in 42 cases. Sensitivity and specificity of USG in detecting pancreatic mass were 80 and 97.6%. CT scan showed 93.3% sensitivity and 97.6% specificity. In case of gallbladder (GB) mass USG found true positive in 20 and 1 false positive. There was no false negative and true negative in 36 cases. CT scan also revealed better sensitivity. USG could not detect any case of periampulla. Conclusion: Accuracy of USG and CT is high in detecting biliary tree dilatation, with CT scan slightly more accurate than USG. The difference in cost between the two is likely to decline with time and make CT even more attractive and handy for imaging the hepatobiliary system.