[Imaging diagnosis of small hepatocellular carcinoma by CT during arterial portography and Lipiodol-CT].

To evaluate the rates of detection for CT during arterial portography (CTAP) and Lipiodol-CT in small hepatocellular carcinoma (HCC), including early stage HCC, a comparative prospective study was performed in 24 candidates for surgery with 39 histopathologically proved lesions: eight lesions of early HCC, four of early advanced HCC and 27 of advanced HCC. The following results were obtained. 1) Ten of 24 patients had multiple primary HCC foci, 70% of which were, moreover, located in different segments. 2) Detection rates for digital subtraction angiography (DSA), CTAP and Lipiodol-CT were 67%, 87% and 72%, respectively. For 13 lesions undetected by DSA, the detection rates for CTAP and Lipiodol-CT were 62% and 31%. 3) For small HCC (n = 16) of less than 2 cm in diameter, CTAP (75%) tended to be superior to Lipiodol-CT (44%). 4) For early HCC (n = 8), CTAP (63%) showed a significantly higher detection rate than Lipiodol-CT (25%). 5) In contrast, detection rates for small (less than or equal to 2 cm) early advanced (n = 3) and advanced HCCs (n = 5) were almost the same: 67% and 100% by CTAP and 67% and 80% by Lipiodol-CT, respectively. To diagnose multiple primary HCCs in a candidate for surgery, CTAP is imperative following angiography.