Nontumorous attenuation changes on CT arterial portography

We prospectively studied the frequency and the distribution of nontumorous attenuation changes during CT arterial portography.

Computed tomography arterial portograms were obtained in 67 consecutive patients. The frequency and distribution of nontumorous attenuation changes (pseudolesions, areas of hypo- or hyperperfusion) were analyzed and related to the size of the tumor, the vascular status assessed by Doppler examination, and the presence of chronic liver disease.

Pseudolesions were detected in 19 patients (28%). They were typical in 13 cases and atypical (round shaped or located in the caudate or right lobe) in 6. Segmental, lobar, or diffuse perfusion defects were seen in 36 patients (54%). In 56% of the cases, they were adjacent to large tumors and related to compression or thrombosis of intrahepatic portal branches as demonstrated by sonographic and Doppler findings. Areas of hyperperfusion were detected in 14 patients (21%). Of these cases, eight (57%) were peritumoral hyperperfusion. In all cases, the mean diameter of the tumors was large and there was compression of adjacent hepatic vein as demonstrated by sonographic and Doppler findings.

Nontumorous attenuation changes are common in CT arterial portography. Factors leading to these artifacts include size of the tumor and vascular consequences of the tumor. Sonographic and Doppler studies may play a role in predicting these factors.