Hemodynamics of small hepatocellular carcinomas (5 cm or less in diameter): cases with discrepant findings between dynamic MR images and hepatic arteriograms.

BACKGROUND: The degrees and patterns of contrast enhancement of small hepatocellular carcinomas (HCCs) on dynamic magnetic resonance (MR) images were compared with those on hepatic arteriograms in 61 patients.
METHODS: Dynamic MR imaging was performed within 1 week before hepatic angiography prior to treatment, 3-4 weeks after treatment, and then once every 1-3 months if necessary. Hepatic arteriography was carried out with a coaxial microcatheter inserted into the proper hepatic artery or its distal branches.
RESULTS: In 58 of 61 cases, the degrees of contrast enhancement of the tumor in dynamic MR imaging were roughly consistent with those in hepatic arteriography before treatment. In the remaining three cases, however, the tumors were depicted as hyperintense in the arterial dominant phase of the dynamic MR imaging, whereas the tumors were not detected by hepatic arteriography. The tumor detectability is 97% by dynamic MR imaging and 92% by hepatic arteriography. Furthermore, when an HCC nodule was not clearly enhanced by hepatic arteriography after treatment, it was possible by dynamic MR imaging to obtain accurate information on whether the HCC nodule had parasitic arteries.
CONCLUSIONS: Dynamic MR imaging was superior to hepatic angiography in contrast resolution. It was therefore considered to be useful in assessing the degrees and patterns of contrast enhancement of small HCCs before and after treatment.