May 19, 2015
Rapid Method for Thermal Dose-Based Safety Supervision During MR Scans
Esra Neufeld, Maximilian Fuetterer, Manuel Murbach, and Niels Kuster, Bioelectromagnetics, Volume 36, Issue 5, pp. 398–407, July 2015, online May 11, 2015
Based on risk/benefit considerations in clinical diagnostics, MRI exposures are allowed to exceed the limits for the general public by more than a factor of 50. However, the well-controlled environment allows for a number of assumptions, including the tissue types where the thermal hotspots typically occur. This study explores a novel safety assessment model that offers maximum flexibility while preventing thermal tissue damage from RF exposure. Based on transient information about the SAR, the current peak tissue temperature can be estimated via exponential approximations of the temperature profiles. The CEM43 thermal dose concept naturally considers exposure duration, tissue sensitivity, and the transient nature of heating. The model is capable of predicting CEM43 for patients with either uncompromised thermoregulation or absent thermoregulation, and herein offers an MRI safety assessment approach that overcomes problems associated with traditional SAR-based limits.
The scientific and technical impact of the study can be summarized as:
- Presentation of a novel and rapid method for RF safety supervision in MRI
- Possibility to consider the thermoregulatory abilities of the patient
- Derivation of the model-parameters from an extensive simulation matrix
- Exploring the advantages of CEM43 thermal dose based supervision
