1Radiotherapy, UMC Utrecht, Utrecht, Netherlands
Recent simulation studies indicate that in clinical MRI experiments local tissue temperature and RF exposure can exceed safety guidelines. By using PRFS MR thermometry and ASL, one can monitor rises in tissue temperatures and perfusion. By combining these techniques during RF heating, we hope to obtain insight in the local thermoregulatory system of the body. Temperature measurements in the calf muscle during a high SAR scan at clinical settings showed that RF heating can lead to significant heating of the outer region of the calf muscle. An increase in perfusion was also detected, in spite of very low perfusion levels.