78 generalized decreased attenuation of the liver

1. 78 Generalized Decreased Attenuation of the Liver

2. CLINICAL IMAGAGING AN ATLAS OF DIFFERENTIAL DAIGNOSIS EISENBERG DR. Muhammad Bin Zulfiqar PGR-FCPS III SIMS/SHL

3. Fig GI 78-1 Fatty infiltration in cirrhosis. Generalized decrease in the attenuation value of the liver (far less than that of the spleen). The portal veins appear as high-density structures surrounded by a background of low-density hepatic fat.

4. Fig GI 78-2 Patchy fatty infiltration in cirrhosis. The right (R) and caudate (c) lobes of the liver are replaced by fat to a degree that makes the density almost equal to that of the gallbladder (G). The medial segment of the left hepatic lobe has a higher CT density but contains foci of low attenuation. The spleen is large, and the caudate lobe is prominent. The portal vein (arrows) courses normally through the center of the right hepatic lobe, distinguishing fatty infiltration from a low-density tumor. 122

5. Fig GI 78-3 Regenerating nodules in cirrhosis. Multiple nodules of attenuation equal to that of normal liver are seen superimposed on a background of low-attenuation fatty infiltration. Note the calcification in the pancreas caused by chronic pancreatitis in this patient, a chronic alcoholic.

6. Fig GI 78-4 Budd-Chiari syndrome. Contrast scan of a woman with a coagulation disorder and hepatic vein thrombosis shows the characteristic mosaic pattern of peripheral low attenuation in both the right and left hepatic lobes. The liver is enlarged with relatively marked hypertrophy of the caudate lobe, which has a uniform attenuation. 129

7. Fig GI 78-5 Budd-Chiari syndrome. Classic flip-flop pattern of hepatic contrast enhancement. (A) Initially, the normally enhancing central part of the liver, including the caudate lobe (CL) and part of the lateral segment of the left lobe (LS), appears hyperdense relative to the periphery of the liver, which enhances more slowly. (B) Later, as the contrast material washes out centrally and accretes peripherally, the central region appears relatively hypodense. Note the thrombus in the hepatic veins (arrows). (A, ascites.) 139

8. Fig GI 78-6 Congestive heart failure. (A) Early bolus-enhanced scan shows dense retrograde hepatic venous opacification. (B) Scan obtained during the vascular phase shows diffusely mottled hepatic enhancement. 140

9. Fig GI 78-7 Amyloidosis. Diffusely enlarged liver with generalized decreased attenuation. 141