Detection of corona enhancement of hypervascular hepatocellular carcinoma by C-arm dual-phase cone-beam CT during hepatic arteriography.

The purpose of this study was to evaluate the detectability of corona enhancement around the hypervascular hepatocellular carcinoma (HCC) by dual-phase cone-beam computed tomography during hepatic arteriography (CBCTHA). Dual-phase CBCTHA was performed for 71 HCC lesions (mean ± SD 1.7 ± 0.9 cm), including seven presenting a nodule-in-nodule appearance and nine hypervascular pseudolesions. The first scan was performed during injection of 30-40 ml half-diluted contrast material at a rate of 1.5-2 ml/s through the hepatic artery. Scanning was initiated 7 s after the beginning of contrast material injection. The second scan was started 30 s after the end of the first scan. Detectability of corona enhancement on second-phase CBCTHA was evaluated. Thickness of corona enhancement was also analyzed as thin (≤2 mm) or thick (>2 mm). Corona enhancement was detected in 63 (88.7%) of 71 tumors (1.8 ± 0.9 cm), but it was not detected in eight tumors (1.0 ± 0.2 cm). Thin corona enhancement was seen in 18 tumors (1.2 ± 0.5 cm), and thick corona enhancement was seen in 45 tumors (2.0 ± 0.9 cm). There was a significant difference in tumor diameter between tumors with and those without corona enhancement (P = 0.0157) and between thin and thick corona enhancement (P = 0.001). In all seven early-stage tumors, corona enhancement was demonstrated around the hypervascular focus within the hypovascular tumor portion. None of the nine pseudolesions showed any corona enhancement. Dual-phase CBCTHA depicted corona enhancement in 88.7% of hypervascular HCC lesions. This technique may improve the diagnostic accuracy of HCC.