[Portal hypertension--current status of ultrasound diagnosis]

Abstract

Splenomegaly, ascites, and anatomy of intra- and extrahepatic portal vessels can reliably be detected by ultrasound in case of portal hypertension. The increased diameter of the portal vein and its roots is a not sufficient sensitive and specific finding in portal hypertension. However a marked variation of diameter at the superior mesenteric vein during in- and expiration is nearly exclusive. With the help of colour flow imaging or duplex sonography additional finding of blood flow in the portal system can be detected noninvasively and continuously. Quantitative blood-flow measurement in routine examinations is unnecessary and reserved to special questions. Reverse flow or significantly decreased blood flow velocity or the detection of portocaval collaterals are reliable findings in portal hypertension. In addition thrombosis of portal vessels and its hemodynamic consequences can be seen. Because underlying diseases e.g. liver cirrhosis or tumours are diagnosed in the same procedure ultrasound techniques are used in first line when portal hypertension is suspected. The findings are complementary to endoscopy of upper g.i.tract and lead on the one hand to a well-aimed use of CT scanning or x-ray splenoportography, and--on the other hand--make them dispensable in a low of cases.