C-arm CT performed during trans-arterial chemoembolization (TACE) allows the detection of hypervascular tumor with high spatial resolution with a thin slice thickness [ 10 ]. In addition, the intra-arterial bolus injection of contrast medium for C-arm CT leads to better contrast-to-noise ratio, especially for hypervascular HCC, than that of CT and MRI [ 11 , 12 ]. According to previously published reports, C-arm CT has been shown to have sufficient image quality for detecting HCCs [ 13 – 15 ].