[Current diagnosis of liver diseases: duplex ultrasonography]

In the last 20 years abdominal sonography has become a powerful method in diagnosing diseases in gastroenterology and hepatology. Now, Doppler techniques are also used for the examination of abdominal vessels and especially of the portal circulation in an increasing number of medical centers. Color Doppler flow imaging (CDFI) represents an extension of duplex sonography as it makes velocity informations available not only for a small region but also for a larger segment or even for the whole image. CDFI indications include all aspects of portal hypertension, liver diseases of unknown origin, and focal liver lesions suspicious for hepatocellular carcinoma. This technique when used by skilled operators provides much information that sometimes cannot be gained in any other way. The CDFI will become a complementary procedure as well as an important alternative to angiographic methods in the diagnosis of vascular disturbances in the portal system.