Fig. 7. RF ablation using parallel targeting along large vessel in 50-year-old man.

A. Gadoxetic acid-enhanced axial hepatobiliary-phase T1-weighted image shows metastasis (arrow) from rectal cancer in segment 7 abutting right hepatic vein (arrowhead). B. Intercostal US image depicts hypoechoic metastasis (arrowhead) abutting right hepatic vein (arrow), which can potentially cause heat-sink effect during RF ablation. C. Intercostal US image during procedure demonstrates needle (arrow) in parallel to right hepatic vein (arrowhead) in order to enlarge contact surface between ablation zone and vessel. D. Immediate follow-up contrast-enhanced CT image shows elongated low-attenuated RF ablation zone (asterisk) along right hepatic vein (arrowhead), which sufficiently covers index tumor, as well as intact right hepatic vein. RF = radiofrequency, US = ultrasound