Sonographic detection of stones in poorly opacified left intrahepatic ducts

Intrahepatic duct (IHD) stone is a common disease in Taiwan. In some cases, left IHD stones cannot be demonstrated by endoscopic retrograde cholangiography (ERC) or even by percutaneous cholangiography (PTC). This study was designed to evaluate the efficacy of sonography in demonstrating left IHD stones in poorly opacified left IHD by either ERC or PTC. Of 109 patients with hyperechoic nodular lesions in either the dilated left IHD or atrophic left lobe of the liver, with or without acoustic shadows, 49 patients were excluded because they refused further study. Among the remainder (60 patients), 33 patients had good opacification of left IHD in ERC or PTC. Stones were seen in 31 patients, and tumor obstruction in 2 patients. Twenty-seven patients had complete or partial absence of the left IHD in cholangiograms. Stones were found at surgery in 23 patients and by CT scan in 3 patients. Mucin-producing cholangiocarcinoma was found in 1 patient. The positive predictive value of the demonstration of stones in left IHD by ultrasound was 95% (57/60). Only 15% of patients with atrophy of the left hepatic lobe and stones were demonstrated by sonogram in this series. We conclude that the detection of left IHD stones by ultrasound in patients with poor opacification of the left IHD in cholangiograms is reliable procedure.