Infrared thermographic measurement of the SAR patterns of interstitial hyperthermia applicators

In the design and quality assurance of hyperthermia applicators, much work has been done in the development of accurate systems for the measurement of specific absorption rate (SAR). The need for higher spatial resolution in SAR measurement systems designed for interstitial applicators has resulted in growing interest in infrared (IR) thermographic measurement. Although IR thermographic measurement has been argued against because of the presence of thermal conduction and convection artifacts in measured SAR patterns, such effects are typically assumed to be negligible, and IR measurement systems continue to see routine use.; In this thesis, the major sources of error and variability in an interstitial IR thermographic SAR measurement system were investigated to determine the accuracy of measured SAR patterns. Conduction and convection artifacts were found to be a considerable source of error in the measured SAR patterns of interstitial microwave and ultrasound applicators for heating durations in excess of 10 to 20 seconds.