Evaluation of MR-induced hot spots for different temporal SAR modes using a time-dependent finite difference method with explicit temperature gradient treatment.

An investigation of magnetic resonance (MR)-induced hot spots in a high-resolution human model is performed, motivated by safety aspects for the use of MR tomographs. The human model is placed in an MR whole body resonator that is driven in a quadrature excitation mode. The MR-induced hot spots are studied by varying the following: (1) the temporal specific absorption rate (SAR) mode ("steady imaging", "intermittent imaging"), (2) the simulation procedure (related to given power levels or to limiting temperatures), and (3) different thermal tissue properties including temperature-independent and temperature-dependent perfusion models.

Implications of clinical RF hyperthermia on protection limits in the RF range.

The systemic temperature is meticulously regulated to 37-37.5 degrees C. Organ systems (skin, digestive system, muscles) have a considerable potential to regulate the perfusion for thermal regulation, physical activity, or digestion.