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.
2. Dormont, D., et al., "Chronic thalamic stimulation with three-dimensional MR stereotactic guidance," Am. J. Neuroradiology, Vol. 18, No. 6, 1093-1097, 1997.
3. Nyenhuis, J. A., 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.
4. Jin, J. M., et al., "Computation of electromagnetic fields for high-frequency magnetic resonance imaging applications," Phys. Med. Biol., Vol. 41, 2719-2738, 1996.
5. Nitz, W. R., 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.
6. Nguyen, U. D., 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.
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.
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.
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.
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.
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.
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.
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.
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.
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, 2006.
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.