Fig. 2

Schematic illustration of proposed CTHA-EM method to predict hepatocellular carcinoma response to DEB-TACE. a CTHA image acquisition during DEB-TACE consists of dual-phase CT (native- and contrast-enhanced arterial phases) acquired before and after DEB-TACE. Pre-treatment CTHA showed hypervascular tumor in segment 8 (white arrow). Posttreatment CTHA showed contrast agent accumulation within the tumor from DEB-TACE along with arterial supply (black arrow), making it difficult to delineate contrast stasis from residual tumor blush. b Pre- and posttreatment dual-phase CTHA images were loaded into a workstation, and software was used to generate CTHA-EM images with deformable registration and subtraction to assess residual tumor enhancement. The tumor was highlighted on pre-treatment CTHA enhancement mapping (white arrow), and no residual tumor enhancement was depicted on the posttreatment CTHA enhancement mapping (dotted circle). Contrast stasis from the posttreatment native CT was subtracted from the arterial phase to show potential residual tumor arterial enhancement. c First follow-up computed tomography imaging after DEB-TACE was used to predict the treatment response accordingly to mRECIST, confirming complete response in this case. CTHA, Computed tomography hepatic arteriography; CTHA-EM CTHA, enhancement mapping; DEB-TACE, Drug-eluting beads transarterial chemoembolization; mRECIST, Modified Response Evaluation Criteria in Solid Tumors