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We evaluated the influence of 3T magnetic resonance imaging whole body birdcage coil modeling on electromagnetic exposure estimation using a human model. Simplification of coil geometry, realistic tuning and capacitor losses had a relevant impact on the estimated electric distributions. Variety of the generated electric field has to be carefully considered for reliable RF safety assessment of a patient with a passive or active implant undergoing magnetic resonance imaging.

For a helix coax lead at 128 MHz using a set of incident electric fields (E tan ) with different profiles we numerically investigate the influence of the temperature sensor location on the evaluation of the calibration factor of the lead electromagnetic model. A shift of the sensor from the electrode tip to the electrode pedestal resulted in a decrease of the linear regression model coefficient from 0.99 to 0.5.

Using several sets of incident electric fields (Etan) with different profiles we estimated the calibration factors of the lead electromagnetic model for two helical coax leads at 128 MHz. The proposed quantities for E tan selection are (i) the unitless ratio of the RF-induced power deposition (P) with the lead in place to P without the lead in place (P backgnd ) and (ii) the percentage of P backgnd for the selected E tan to that P backgnd generated by a homogeneous E tan .