Figure 3c:

Evolution of imaging findings after microwave ablation (MWA) with subsequent recurrent disease. Images from a 62-year-old woman with biopsy-proven hepatocellular carcinoma (HCC) (arrow). (a) A 3.0-cm peripheral arterial enhancing lesion with central hypoenhancement pretreatment, compatible with an LR M lesion. (b) One month after MWA therapy there was an expected increase in size of the treated lesion with a complete lack of central enhancement, consistent with treated HCC (mRECIST CR, LI-RADS TR nonviable). Adjacent to the ablation zone there was a peripheral wedge-shaped area of arterial phase hyperenhancement (arrowhead) which persists on the portal venous phase without washout (c), favored to represent posttreatment perfusional changes. (d) Twelve months after ablation, the treated HCC continues to decrease in size with no central enhancement. However, there is a large nodular area of arterial enhancement (arrowhead in d) demonstrating washout (arrowhead in e), compatible with recurrent HCC (mRECIST PD, LI-RADS TR viable). CR = complete response, LI-RADS = Liver Imaging and Reporting Data System, mRECIST = modified Response Evaluation Criteria for Solid Tumors, PD = progressive disease, TR = treatment response.