CT appearance of hepatic parenchymal changes after percutaneous microwave coagulation therapy for hepatocellular carcinoma

Purpose: The purpose of this study was to evaluate the changes in the CT appearance of the hepatic parenchyma surrounding the necrotic area in the early period after percutaneous microwave coagulation therapy (PMCT) for hepatocellular carcinoma (HCC). Method: We reviewed enhanced CT scans obtained before and within 2 weeks, at 1 month, and at 3 months after PMCT of 61 lesions in 47 patients with HCC. Results: On dynamic CTI early enhancement of the hepatic parenchyma around the treated area was a frequent finding within 1 (87%) or 2 (68%) weeks after PMCT, but such enhancement disappeared on follow-up. Arterioportal shunts were also demonstrated by enhanced CT after treatment (21% at less than or equal to2 weeks), and these shunts tended to persist for >1 month. Conclusion: We should evaluate the effect of PMCT by performing dynamic enhanced CT not only within 2 weeks to determine the end-point of treatment but also at 1 month or more after finishing treatment for definite assessment of tumor necrosis.