SAR Simulations & Safety

Abstract

Overview

Radiofrequency (RF) safety at ultra-high fields incorporates complex challenges not present at lower field strengths. The use of multi-channel RF transmit coils alongside parallel transmit techniques results in both time-variable and spatially heterogeneous power loss densities within the body tissues.

Key Developments

• Detailed discussion on the transition from quasi-stationary to electromagnetic field regime in high-field systems, highlighting the increased need for localized field data.
• Examination of numerical RF and thermal simulation methods as essential tools for accurate local mapping of magnetic, electric fields, and tissue temperatures.

Importance of Thermal Effects

Consideration of local tissue temperatures is gaining importance as it reflects more directly the potential for tissue damage.

• Insight into bio-heat transfer models and physiological response considerations during RF exposure.

Advancements in SAR Monitoring

Discussion on the innovation of simulation-based specific absorption rate (SAR) matrix models helps in designing RF pulses with constraints on local SAR in multi-channel MR systems. This ensures enhanced safety and regulation compliance during MR exams.