To illustrate various pathways of portosystemic communication on patients with portal hypertension, to describe them as they appear on CT scans, to classify and try to determine their significance in the pathological context.

PORTAL HYPERTENSION Normal pressure in the portal system varies between 5 and 10 mmHg. Normal hepatic blood flow of 550-900 ml/min (~ 25 % of cardiac output) passes through portal system (2/3) and through hepatic artery (1/3) [1]. Portal hypertension is defined as portal venous pressure greater than 10 mmHg. Two important factors exist in the pathopysiology of portal hypertension[2]: 1. Vascular resistance and 2. Blood flow. The relation between these two factors and portal pressure is defined by the following formula: P=FR Where P-...

PORTAL VENOUS SYSTEM Portal Vein The portal vein is about 7 to 8 cm in length and carries the visceral blood to the liver, where it ramifies following the segmental pattern, reaching the sinusoids, from which the blood again converges to drain into the inferior vena cava through the hepatic veins. The portal vein results from the confluence of the splenic vein and the superior mesenteric vein. Besides the splenic and the superior mesenteric veins, other tributaries are the left gastric, right gastric, the paraumbilical,...

Computed tomography is capable of accurately demonstration of many of the varied manifestations of portal hypertension. The portosystemic collateral channels that can develop in portal hypertension secondary to cirrhosis are numerous and may vary in appearance. It is important for the radiologist to be familiar with aspects which may be present on cirrhotic patient, describe them and try to identify the dominant diversion paths.

1. Dahnert W. Radiology Review Manual, 6th Edition, 2007 p774-775 2. Carale J, Mukherjee S. Portal Hypertension. eMedicine Gastroenterology 2010. 3. Uflacker R. Atlas of Vascular Anatomy: An Angiographic Approach, 2nd Edition 2007. 4. Cho KC, Patel YD, Wachsberg RH, Seeff J. Varices in portal hypertension: Evaluation with CT. Radiographics 1995: 609-22. 5. Ahn J, Cooper JM, Silberzweig JE, Mitty HA. Venographyc appearance of portosystemic collateral pathways. The British Journal of Radiology 70 (1997), 1302-1036.