MR-tomography on patients with heart pacemakers-a numerical study

Abstract

Patients having a heart pacemaker are not allowed to go to MR tomography (MRT). One of the most dangerous effects is the heating of the tissue around the electrode caused by the coupling to the RF field of the MR system. Experiments have been carried out using tanks filled with saline water and large heating has sometimes been observed. Other experiments e.g. with electrodes in the brain did not show any heating at all. In this work numerical studies have been carried out to understand the different results. In conclusion it is suggested that MRT could be possible if the "normal" geometry of the wires of a heart pacemaker is ensured and an open MR system is used.

Safety aspects of magnetic resonance imaging for pacemaker holders

“…With this model, a peak SAR averaged over 1 g of 2 W/kg near the metallic implant (compared to the value of 1.8 W/kg at the same location without the metallic implant) has been computed and no appreciable heating has been obtained. Similar results have been obtained in [15].…”

Interaction between the RF Field of MRI Apparatus and Pacemakers

“…With this model, a peak SAR averaged over 1 g of 2 W/kg near the metallic implant (compared to the value of 1.8 W/kg at the same location without the metallic implant) has been computed and no appreciable heating has been obtained. Similar results have been obtained in Golombeck & Dossel (2004) and Stuchly et al (2006). In order to investigate the effects of the PM geometrical parameters Pisa et al (2008) studied the exposure to a power of 100 W at 64 MHz of a box model of the thorax in the presence of a pacemaker with a unipolar catheter.…”

“…The most used is a simple bare cylindrical copper wire (see Fig. 11a) with various diameters and lengths (Ho, 2001;Golombeck & Dossel, 2004;Stuchly et al, 2006;Pisa et al, 2008), while a more realistic version is constituted by a copper wire covered with plastic (see Fig. 11b).…”

Magnetic‐Guided Percutaneous Coronary Intervention Enabled by Two‐Dimensional Guidewire Steering and Three‐Dimensional Virtual Angioscopy: Initial Experiences in Daily Clinical Practice

“…Three patients with prior implantation of VVIR pacemaker and VVI and DDD defibrillatorcardioverter, respectively, successfully underwent the intervention despite exposure to the relatively strong magnetic field influence. [22][23][24] One device switched into magnet mode during the procedure. No arrhythmia induction occurred.…”