Figure 8b. Microwave ablation of a hepatic metastasis in an 82-year-old woman with a cardiac pacemaker and metastatic colon cancer to both lung and liver. She had responded well to chemotherapy and had only one hepatic lesion, measuring approximately 4.3 cm in greatest diameter, in liver segment 7. (a) CT scan shows three single microwave antennae, which were positioned with fluoroscopic guidance in the center of the lesion. Two 10-minute, 45-W ablations were performed. (b, c) Contrast-enhanced CT scans obtained immediately after the procedure in the arterial (b) and portal venous (c) phases show successful microwave ablation of the lesion, with an area of thermocoagulation (arrows) measuring 5.3 cm in greatest diameter. Surrounding peripheral hyperemia represents postablation changes at the site of the lesion. No immediate complications were observed.