Flexion Effect on the Radiofrequency-Induced Heating for Modular External Fixation

This paper studies the influence of flexion on radiofrequency (RF) – induced heating for patients with modular external fixation under 1.5 Tesla (T) and 3T magnetic resonance imaging (MRI) systems. Four configurations of a modular external fixation are developed to suit different patients' postures. They are applied at the same position on the patient's body. Numerical simulations are performed with patients loaded at three imaging landmarks. RF-induced heating in terms of peak averaged specific absorption rate (SAR) over 1 gram (peak
$text{SAR}_{\mathbf{1}\mathbf{g}})$
near the device is evaluated. The variation of peak
$\text{SAR}_{\mathbf{1}\mathbf{g}}$
is up to 44% at 1.5T and 48% at 3T due to the flexion of modular external fixation. Therefore, it is recommended flexion impacts should be considered for the RF-induced heating of modular external fixation.