Increased lymphatic flow from the liver in different intra- and extrahepatic diseases demonstrated by CT

Increase in the production of hepatic lymph is a compensatory mechanism known to occur in cirrhosis, neoplasia of the liver, biliary obstruction, and right-sided cardiac decompensation with elevated hepatic venous pressure. In hepatic lymphostasis, dilated hepatic lymphatics are reflected on CT as low attenuation rims--perivascular lucencies (PVLs)--surrounding the portal veins and the intrahepatic vena cava. In this study, CT scans of the livers of normal controls and patients in each of the four disease categories mentioned above were evaluated for the presence of PVLs; the presence/absence of PVLs was correlated with other CT findings and various biochemical and pathophysiologic parameters. The PVLs were seen with some frequency in patients in each of the four disease categories (12-52%) but in none of the normal controls. In patients with tricuspid incompetence, the presence of PVLs correlated perfectly with the presence of mottled enhancement of the hepatic parenchyma (evidence of sinusoidal stasis). The presence of PVLs was associated with elevation of certain biochemical parameters, but no common biochemical marker was observed across the disease categories. Perivascular lucencies on CT reflect altered hepatic lymphatic dynamics; in the absence of impaired efferent lymph drainage, they reflect increased lymphatic flow. However, the sensitivity of the finding--the relationship of the presence/absence of PVLs on CT to the degree of alteration of the lymphatic dynamics--has yet to be assessed.