Fig. 2

Arterial phase images and corresponding AEF color maps of three representative transverse planes 4 days before (a-f) and 34 days after ( g- l) DEB-TACE from a 76 years old, male, HCC patient who had SD response according to mRECIST. Before treatment, a heterogeneously enhanced HCC lesion was located at the right lobe, with significantly higher AEF (\(\frac{70\%+63\%+69\%}{3}=67.3\%\), showed as red and yellow region) than surrounding liver parenchyma (\(\frac{18\%+12\%+15\%}{3}=15.0\%\), showed as blue and purple region). After treatment, the necrosis of tumor induce by embolization showed as signal loss on the AEF color map, whereas the AEF of residual viable tumor (\(\frac{59\%+56\%+65\%}{3}=60.0\%\)) remain higher than surrounding parenchyma (\(\frac{10\%+12\%+15\%}{3}=12.0\%\)). DEB-TACE: drug-eluting bead transarterial chemoembolization; HCC: hepatocellular carcinoma; SD: stable disease; mRECIST: modified response evaluation criteria in solid tumors; AEF: arterial enhancement fraction