Comparison of ultrasonography and cholangiography (ERCP/PTC) in the differential diagnosis of obstructive jaundice

Diagnostic accuracy of ultrasonography and cholangiography (ERCP/PTC) was compared in determining the site and nature of obstruction in obstructive jaundice. Ultrasound was performed in 50 patients with clinical diagnosis of obstructive jaundice. All patients subsequently underwent ERCP/PTC and/or surgery. ERCP was performed in 38 and PTC in 15 patients. The positive predictive value for the site and etiology of obstruction by ultrasonography was 94% and 86% respectively. In comparison, the cholangiography (ERCP/PTC) had positive predictive value of 100% in site and 98% in etiology. High degree of accuracy and non-invasiveness makes ultrasound as the primary radiological tool in the differential diagnosis of obstructive jaundice. ERCP is the gold standard for determining the precise level and cause of obstruction. PTC adds further to ultrasound based diagnosis of obstructive jaundice particularly in proximal obstruction and in ERCP failure.