IMaging Abdomen

• Cirrhosis results in disproportionate diminution of the right lobe compared to the left lobe and caudate lobe of the liver
• Nodular regeneration of the liver results in a nodular edge of the liver and inhomogeneity of the parenchyma. The process is accompanied by, first, increased resistance to normal hepatopetal (toward the liver) flow and, finally, the development of hepatofugal (away from the liver) flow. The increased resistance in the portal vein secondarily enlarges the spleen. This process also creates enlarged collateral venous channels to reroute blood around the liver . These portosystemic collaterals are visible frequently on cross-sectional imaging studies, most commonly in paraumbilical veins, coronary veins, and even spontaneous splenorenal shunts. Ascites is nearly always present. Most authorities are increasingly convinced that MR imaging is the most sensitive imaging modality for examination of the liver in cirrhosis and other diffuse diseases of the liver. MR imaging can demonstrate not only the contour changes and collateral formation visible with CT, but also the more subtle intraparenchymal nodular changes consequent to formation of regenerative and dysplastic nodules characteristic of cirrhosis within the complex fibrotic and inflamed host hepatic tissue . Importantly, MR imaging is considered to be a sensitive imaging means in the diagnosis of tumors such as hepatocellular carcinoma superimposed on a background of cirrhosis .