On the sensitivity of the skull thickness for the SAR assessment in the intracanial tissues

Specific absorption rate (SAR) simulation may be used to assess exposure levels, health risk and compliance with recommendations of wireless devices EMF exposure limits. When developing a numerical model of a human head the segmentation system decides the boundary between the modeled tissues. E.g., using different strategies (thresholds or parameters) some tissues may be modeled thinner or thicker. The objective of this work is to investigate the sensitivity of the skull thickness in the SAR. Starting with a single DICOM study, two models differing only in the skull thickness were developed. The bones mass of one of the models were 35% lighter than the other's. Under the same exposure conditions, the 1g-psSAR in the brain of the “thin skull” model was 5% higher than the 1g-psSAR of the “thick skull” model. This difference applies to the particular conditions of the performed simulations, then we can conclude that the expected uncertainty related to the skull modelling is of this order of value. We also can expect higher SAR differences corresponding to age related skull thickness differences between children and adults.