Late Phase Images in Whole Liver Double Phase CT during Hepatic Arteriography in the Diagnosis of Well-differentiated Hepatocellular Carcinomas

「Summary.」Early phase images by double phase CT during hepatic arteriography (CTHA-1) and CT during arterial portography (CTAP) are useful for detecting and characterizing, well-differentiated hepatocellular carcinomas (HCCs). Still, the development of even more accurate diagnostic methods is desired. We therefore evaluated late phase images of double phase CTHA (CTHA-2) for the detection and characterization of HCCs. We analyzed the findings of CTHA-2 in 20 well-differentiated HCC nodules. Fourteen nodules were well-differentiated HCCs, 1 was well-differentiated HCC with adenomatous hyperplasia, and 5 were mixed with well- and moderately (or poorly) differentiated HCCs (wd+mpd-HCC). A combination of CTHA-1 and CTAP could not reveal 2 of 5 were wd+mpd-HCC nodules; however CTHA-2 suggested dedifferentiation of the nodules. In conclusion, CTHA-2 clearly demonstrated the dedifferentiation of well-differentiated HCCs.