CT appearance of hepatic tumors after microwave coagulation therapy.

The purpose of this study was to evaluate the changes in treated lesions and surrounding parenchyma of the liver as well as associated findings on CT in patients who underwent microwave coagulation therapy for hepatic tumors.We retrospectively reviewed the findings on helical dynamic CT scans obtained before and after percutaneous or intraoperative microwave coagulation therapy for 74 lesions in 63 patients with hepatocellular carcinoma or metastatic hepatic tumors. Indications for microwave coagulation therapy included primary hepatic tumors in 54 patients and hepatic metastasis in nine patients. Sixty percent nonionic contrast material, infused at 3 ml/sec, was followed by sequential arterial phase, portal venous phase, and equilibrium phase helical CT of the entire liver in all patients.All lesions were hypodense and extended to the liver capsule. The lesions treated with percutaneous microwave coagulation therapy were teardrop-shaped, whereas those treated with intraoperative microwave coagulation the...