Improvement of MR temperature monitoring for microwave thermocoagulation therapy of liver tumors

Abstract

Respiratory movement disturbed MR temperature monitoring during microwave thermocoagulation of liver tumors, because MR temperature map was highly susceptible to motion. To obtain reliable MR temperature maps, it was required to suspend artificial ventilation during general anesthesia. Microwave ablations ware usually repeated many times in one procedure. Therefore, it was difficult to apply MR temperature monitoring to all of the ablations. We have developed new respiratory triggering technique for temperature monitoring utilizing the information of air way pressure, which was monitored for the control of general anesthesia. Since the ventilation was completely periodical and reproducible, respiratory triggering successfully obtained artifact-free temperature maps without suspending ventilation. This technique made it easy to apply MR temperature monitoring to the repeated microwave ablations and increased the safety of this procedure.