Numerical Simulation of Experimental Investigation of thermal Effects of RF-Fields on Patients During MRI

Abstract

The application of radio-frequency electromagnetic fields during Magnetic Resonance imaging causes electric currrents and dielectric losses in the biological tissues of the patient during Magnetic Resonance procedures. The power deposition inside the human body leaddes to tissues temperature elevation. This phenomenon of whole body heating is unavoidable and of growing concern, since advanced imaging sequences as well as the trend towards high-field Magnetic Resonance scanners, lead to increased power depostion inside the human body. Therefore it becomes more and more important to incorporate the thermal aspect in the process of RF coil design. This paper presents a numerical model based on the finite element method to predict the thermophysiological responses in human subjects during Magnetic Resonance Imaging . The simulation model includes the specific absorption rate distributation inside an anatomically shaped model of the human body, the bioheat-transfer-equation, and a mathematical model of human thermoregulation. The model is applied to a real imaging situation and validated experimentally by temperature measurements. The comparison between experimental and numerical results shows good agreement.