Heterogeneous hepatic enhancement on CT angiography in idiopathic portal hypertension.

Background: Idiopathic portal hypertension is an uncommon condition characterized by presinusoidal portal perfusion disturbance without known causes. Methods: In the present study, portal and arterial perfusion dynamics were evaluated in two cases with idiopathic portal hypertension using computed tomography during arterial portography and hepatic arteriography. Ten cases with liver cirrhosis were also studied as a reference. Results: In cases with idiopathic portal hypertension, portal perfusion was conspicuously heterogeneous and decreased especially at the periphery of the liver where arterial perfusion was reciprocally increased. When the spatial heterogeneity of an enhancement of the liver was quantified using a densitometric analysis of computed tomography during hepatic arteriography images, the densities at the periphery were higher and varied more than those of the inner areas in cases with idiopathic portal hypertension. In contrast, the densities did not vary between the periphery and the inner areas at the cases with liver cirrhosis. Conclusions: The heterogeneous increase of arterial perfusion in periphery of the liver may be an important feature of idiopathic portal hypertension.