volume | PIER Journals

Abstract

We have investigated the scattering of the Magnetic Resonance Imaging (MRI) radiofrequency (RF) field by implants for Deep Brain Stimulation (DBS) and the resultant heating of the tissue surrounding the DBS electrodes. The finite element method has been used to perform full 3-D realistic simulations. The near field has been computed for varying distances of the connecting portion of the lead from the air-tissue interface. Dissipated powers and induced temperature rise distributions have been obtained in the region surrounding the electrodes. It is shown that the near proximity of the air-tissue interface results in a reduction in the induced temperature rise.

1. Rezai, A. R., D. Finneli, J. A. Nyenhuis, G. Hrdlicka, J. Tkach, A. Sharan, P. Rugieri, et al. "Neurostimulation systems for deep brain stimulation: In vitro evaluation of magnetic resonance imaging-related heating at 1.5 Tesla," J Magn. Reson. Imaging, Vol. 15, No. 3, 241-250, 2002.
doi:10.1002/jmri.10069 Google Scholar

2. Dormont, D., P. Cornu, B. Pidoux, et al. "Chronic thalamic stimulation with three-dimensional MR stereotactic guidance," Am. J. Neuroradiology, Vol. 18, No. 6, 1093-1097, 1997. Google Scholar

3. Nyenhuis, J. A., S. M. Park, et al. "MRI and implanted medical devices: Basic interactions with an emphasis on heating," IEEE Trans. Device and Materials Reliability, Vol. 5, No. 3, 467-480, 2005.
doi:10.1109/TDMR.2005.859033 Google Scholar

4. Jin, J. M., J. Chen, W. C. Chew, et al. "Computation of electromagnetic fields for high-frequency magnetic resonance imaging applications," Phys. Med. Biol., Vol. 41, 2719-2738, 1996.
doi:10.1088/0031-9155/41/12/011 Google Scholar

5. Nitz, W. R., A. Oppelt, W. Renz, et al. "On the heating of linear conductive structures as guide wires and catheters in interventional MRI," J. Magn. Reson. Imag., Vol. 13, No. 1, 105-114, 2001.
doi:10.1002/1522-2586(200101)13:1<105::AID-JMRI1016>3.0.CO;2-0 Google Scholar

6. Nguyen, U. D., J. S. Brown, et al. "Numerical evaluation of heating of the human head due to magnetic resonance imaging," IEEE Trans. Biomed. Eng., Vol. 51, No. 8, 1301-1309, 2004.
doi:10.1109/TBME.2004.827559 Google Scholar

7. King, R. W. P., B. S. Trembly, and J. W. Strohbehn, "The electromagnetic field of an insulated antenna in a conducting or dielectric medium," IEEE Trans. MTT, Vol. 31, No. 7, 574-583, 1983.
doi:10.1109/TMTT.1983.1131547 Google Scholar

8. King, R. W. P., "Antennas in material media near boundaries with application to communication and geophysical exploration, Part I: The bare metal dipole," IEEE Trans. on Anten. and Prop., Vol. 34, No. 4, 483-489, 1986.
doi:10.1109/TAP.1986.1143848 Google Scholar

9. King, R. W. P., "Antennas in material media near boundaries with application to communication and geophysical exploration, Part II: The terminated insulated antenna," IEEE Trans. on Anten. and Prop., Vol. 34, No. 4, 490-496, 1986.
doi:10.1109/TAP.1986.1143843 Google Scholar

10. Atlamazoglou, P. E. and N. K. Uzunoglu, "Galerkin moment method for the analysis of an insulated antenna in a dissipative dielectric medium," IEEE Trans. MTT, Vol. 44, No. 7, 988-996, 1998.
doi:10.1109/22.701454 Google Scholar

11. Park, S. M., R. Kamondetdacha, A. Amjad, and J. A. Nyenhuis, "MRI safety: RF induced heating on straight wires," IEEE Trans. Magn., Vol. 41, No. 10, 4197-4199, 2005.
doi:10.1109/TMAG.2005.854803 Google Scholar

12. Volakis, J. L., A. Chatterjee, and L. C. Kempel, "Review of the finite-element method for three-dimensional electromagnetic scattering," J. Opt. Soc. Am. A, Vol. 11, No. 4, 1422-1433, 1994. Google Scholar

13. Jin, J. M., The Finite Element Method in Electromagnetics, 2nd Ed., John Wiley and Sons, 2002.

14. Park, S. M., Ph.D. thesis, Purdue University, West Lafayette, IN, 2006.

15. Ibrahiem, A., C. Dale, W. Tabbara, and J. Wiart, "Analysis of the temperature increase linked to the power induced by RF source," Progress In Electromagnetics Research, Vol. 52, 23-46, 2005.
doi:10.2528/PIER04062501 Google Scholar

16. Kuo, L.-C., Y.-C. Kan, and H.-R. Chuang, "Analusis of a 900/1800-Mhz dual-band gap loop antenna on a handset with proximate head and hand model," Journal of Electromagnetic Waves and Applications, Vol. 21, No. 1, 107-122, 2007.
doi:10.1163/156939307779391722 Google Scholar

17. Khalatbari, S., D. Sardari, A. A. Mirzaee, and H. A. Sadafi, "Calculating SAR in two models of the human head exposed to mobile phones radiations at 900 and 1800 MHz," PIERS Online, Vol. 2, No. 1, 104-109, March 26 2006.
doi:10.2529/PIERS050905190653 Google Scholar

18. Kouveliotis, K. and C. N. Capsalis, "Prediction of the SAR level induced in a dielectric sphere by a thin wire dipole antenna," Progress In Electromagnetics Research, Vol. 80, 321-336, 2008.
doi:10.2528/PIER07112804 Google Scholar

Professor Syed Mohsin

Dr. Noor Sheikh

Mr. Usman Saeed