Microwave coagulation therapy on hepatomas: CT and MR appearance after therapy

Laparoscopic microwave coagulation (LMC) for hepatocellular carcinomas (HCC s) was performed on 26 HCCs in 17 patients, Contrast-enhanced CT (CECT) and MR images T1-weighted imaging [T1WI], T2WI, gadolinium-diethylenetriamine pentaacetic acid Gd-DTPA T1WI were obtained to determine changes over time, The irradiated center exhibited low to moderate intensity with surrounded high intensity (HI) on T2WI and Gd-DTPA T1WI. On T1WI, lesions showed four patterns of intensity: uniform HI (30.8%), arcuate HI (26.9%), mainly low w ith spot HI (30.8%), and isointensity to hypointensity (11.5%). Follow-up i maging at more than 170 days revealed isointensity to hypointensity on T1WI (96.2%) and reduced HI on T2-weighted imaging (T2WI) and Gd-DTPA T1WI. All lesions became less conspicuous and were reduced in volume. HCC shows time -related changes in signals and size after LMC. Identifying the irradiated lesion is necessary to estimate the adequacy of treatment by comparison wit h the pretherapeutic image.