Ultrasound tomography of the liver: Non-invasive method of choice for the differential diagnosis of jaundice.

Grey-scale ultrasound tomography was used to examine the liver and biliary tree of 100 consecutive unselected jaundiced patients in a prospective study. It was successful in differentiating between hepato-cellular and obstructive jaundice in 94%. It precisely localised the site of obstruction in 75% of those patients with enlargement of the head of the pancreas from either carcinoma or gall-stones impacted in the Ampulla of Vater. This figure was reduced to 60% when all cases of obstruction were considered. Cirrhosis and chronic active hepatitis were found to be associated with an abnormal pattern of echoes within the liver. These echoes were stronger and more numerous than normal. This association was not apparent with drug-induced cholestasis or acute viral hepatitis. Grey-scale ultrasound tomography is quick, safe and completely non-invasive. It should be the initial investigation of choice in the differential diagnosis of jaundice. When precise localisation of an obstruction is not possible after a repeat attempt, then percutaneous transhepatic cholangiography should be considered.