Figure 2c:

Expected imaging findings after microwave ablation (MWA). Axial images from a 57-year-old woman with cirrhosis show a (a) 2.3-cm arterial enhancing lesion (arrow) with washout (b), consistent with hepatocellular carcinoma LI-RADS 5/OPTN 5B. (c) One month after MWA, the tumor size increased by more than 25%, with central T1 precontrast hyperintense signal secondary to coagulation necrosis after MWA. (d) Arterial phase imaging 1 month after MWA shows no residual central tumoral enhancement, confirmed with subtraction images (not shown) (mRECIST CR, LI-RADS TR nonviable). Peripheral rim of smooth continuous enhancement represents granulation tissue (arrowhead). (e) Image from 9 months after MWA shows the lesion regressed in size, with persistence of the thin smooth continuous peripheral rim of enhancement. CR = complete response, LI-RADS = Liver Imaging and Reporting Data System, mRECIST = modified Response Evaluation Criteria for Solid Tumors, OPTN = Organ Procurement and Transplantation Network, TR = treatment response.