Investigation of RF-Induced Heating Near Interventional Catheters at 1.5 T MRI: A Combined Modeling and Experimental Study

This study investigated the radiofrequency-induced heating due to interventional catheters at 1,5 T magnetic resonance image (MRI) based on a combined modeling and experimental method. Two types of interventional catheters, a “single wire” and a “dual wire” catheter, were studied. They were modeled inside a high-resolution anatomical human model along four trajectories. In total, 4 insertion depths, from 17.5 to 70 cm, and 13 scanning landmarks were studied to cover various clinically relevant scenarios. The computational model for the catheters was based on a transfer function approach, measured using the reciprocity theorem. Results of the study showed that the upper limit of the temperature rises near the catheter tip may reach up to 100 °C when scaled to the 2 W/kg average whole-body specific absorption rate (SAR). The computational model was validated experimentally by measuring the induced heating near the catheter in a gel-filled phantom. The data showed a good agreement between the result obtained by the combined method and the direct measurement method with a difference of less than 1 °C. The results suggest that the proposed combined approach, based on the transfer function method, may accurately and efficiently predict the temperature rises near ablation catheters at 1,5 T MRI exposure.