Numerical Computation of Specific Absorption Rate and Induced Current for Workers Exposed to Static Magnetic Fields of MRI Scanners

Abstract

Currently-used Magnetic Resonance Imaging (MRI) scanners in Cairo City possess static magnetic field (SMF) that varies from 0.25 up to 3T. More than half of them possess SMF of 1.5T. Workers in MRI environments are exposed to static magnetic fields. This research paper presents a novel approach for numerical computation of induced current density and Specific Absorption Rate (SAR) values by estimation of fringe static magnetic fields. Iso-gauss line of MR was mapped and a polynomial function of the 7th degree was generated and tested. Induced current due to worker motion in the SMF and SAR values for organs and tissues have been calculated. Results illustrate that the computation tool used permits quick accurate MRI iso-gauss mapping and calculation of induced current and SAR values which can then be used for assessment of occupational exposure profile of MRI operators.