Summation of CT scans during radiofrequency ablation for assessing target lesion coverage.

Objective: In radiofrequency ablation of lesions that require probe repositioning, distinguishing between treated and untreated regions can be difficult. We describe a method of using existing CT equipment to summate images of a current probe placement with those of earlier placements or scans of transiently enhancing targets.

Conclusion: Summation of CT scans during radiofrequency ablation involving multiple probe placements is feasible and results in a better appreciation of probe positioning relative to the target lesion.