Gaussian Beam Modeling of SAR Enhancement in Paraxial and Non-Paraxial Regions of Biological Tissues

doi:10.2528/PIERM09121808

PIER M
Progress In Electromagnetics Research M	ISSN: 1937-8726

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GAUSSIAN BEAM MODELING OF SAR ENHANCEMENT IN PARAXIAL AND NON-PARAXIAL REGIONS OF BIOLOGICAL TISSUES

By M. L. Lumori

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Abstract:
A polarized 3D-electromagnetic wave propagating from an aperture source into a lossy medium can be modeled by an astigmatic Gaussian beam model (GBM) of complex source coefficients that characterize a radiating antenna uniquely. The source coefficients are determined numerically from phantom experiments, and then used in simulations of specific absorption rates (SAR), in both homogeneous and layered biological media, resulting in good agreement with experimental data. This paper shows that for an x-polarized E-field the GBM simulations of SAR enhancement or focus in the axial, z-directed, paraxial region are accurate, but approximate in the transverse, y-directed, non-paraxial regions due to a focal shift.

Citation:
M. L. Lumori, "Gaussian beam modeling of SAR enhancement in paraxial and non-paraxial regions of biological tissues," Progress In Electromagnetics Research M, Vol. 11, 1-12, 2010.
doi:10.2528/PIERM09121808
http://www.jpier.org/pierm/pier.php?paper=09121808

References:
1. Andersen, J. B., "Electromagnetic power deposition: Inhomogeneous media, applicators and phased arrays ," Physics and Technology of Hyperthermia, S. B. Field and C. Franconi (eds.), 159-188, Dordrecht, Martinus Nijho®, The Netherlands, 1987.

2. Lumori, M. L. D., Microwave power deposition in bounded and inhomogeneous lossy media, Ph.D. Dissertation, Department of Electrical and Computer Engineering, University of Arizona, Tucson, May 1988.

3. Lumori, M. L. D., "Experimentally based modeling of field sources for three-dimensional computation of SAR in electromagnetic hyperthermia and treatment planning ," IEEE Trans. Microwave Theory Tech., Vol. 48, 1522-1530, 2000.
doi:10.1109/22.869003

4. Lumori, M. L. D., J. B. Anderson, M. K. Gopal, and T. C. Cetas, "Gaussian beam representation of aperture fields in layered, lossy media: Simulation and experiment," IEEE Trans. Microwave Theory Tech., Vol. 38, 1623-1630, 1990.
doi:10.1109/22.60008

5. Lumori, M. L. D., J. W. Hand, M. K. Gopal, and T. C. Cetas, "Use of Gaussian beam model in predicting SAR distributions from current sheet applicators ," Phys. Med. Biol., Vol. 35, 387-397, UK, 1990.
doi:10.1088/0031-9155/35/3/007

6. Gopal, M. K., J. W. Hand, M. L. D. Lumori, S. Alkhairi, K. D. Paulsen, and T. C. Cetas, "Current sheet applicator arrays for superficial hyperthermia of chestwall lesions," Int. J. Hyperthermia, Vol. 8, 227-240, 1992.
doi:10.3109/02656739209021778

7. Prior, M. V., M. L. D. Lumori, J. W. Hand, G. Lamaitre, C. J. Schneider, and J. D. P. Van Dijk, "The use of current sheet applicator arrays for superficial hyperthermia: Incoherent versus coherent operation," IEEE Trans. Biomed. Eng., Vol. 42, 694-698, 1995.
doi:10.1109/10.391168

8. Deschamps, G. A., "Gaussian beam as a bundle of complex rays," Electron. Lett., Vol. 7, No. 23, 684-685, Nov. 1971.
doi:10.1049/el:19710467

9. Deschamps, G. A., "Ray techniques in electromagnetic," Proc. IEEE, Vol. 60, 1022-1035, Sep. 1975.

10. Kogelnik, H., "On the propagation of Gaussian beams of light through lenslike media including those with loss or gain variation ," App. Opt., Vol. 4, No. 12, 1562-1569, 1965.
doi:10.1364/AO.4.001562

11. Kogelnik, H. and T. Li, "Laser beams and resonators," Proc. IEEE, Vol. 5, No. 10, 1550-1567, 1966.

12. Arnaud, J. A. and H. Kogelnik, "Gaussian light beams with general astigmatism," Appl. Opt., Vol. 8, No. 8, 1687-1693, 1969.
doi:10.1364/AO.8.001687

13. Lovisolo, G. A., et al., "A multifrequency water-filled waveguide applicator: Thermal dosimetry in vivo," IEEE Trans. Microwave Theory Tech., Vol. 32, No. 8, 893-896, 1982.
doi:10.1109/TMTT.1984.1132799

14. Johnson, R. H., "New type of compact electromagnetic applicator for hyperthermia in the treatment of cancer ," Electron. Lett., Vol. 22, 591-593, 1986.
doi:10.1049/el:19860402

15. Johnson, R. H., A. W. Preece, J. W. Hand, and J. R. James, "A new type of lightweight low-frequency electromagnetic hyperthermia applicator," IEEE Trans. Microwave Theory Tech., Vol. 35, 1317-1321, 1987.
doi:10.1109/TMTT.1987.1133854

16. Wait, J. R. and M. L. D. Lumori, "Focused heating in cylindrical targets, Part II," IEEE Trans. Microwave Theory Tech., Vol. 134, 357-359, 1986.
doi:10.1109/TMTT.1986.1133345

17. Lumori, M. L. D., J. R. Wait, and T. C. Cetas, "Power deposition and focusing in a lossy cylinder by a concentric phased array," Radio Science, Vol. 24, 433-442, 1989.
doi:10.1029/RS024i004p00433

18. Stogryn, A., "Equations for calculating the dielectric constant of saline water ," IEEE Trans. Microwave Theory Tech., Vol. 19, No. 8, 733-736, 1971.
doi:10.1109/TMTT.1971.1127617

19. Ebrahimi-Ganjeh, M. A. and A. R. Attari, "Study of water bolus effect on SAR penetration depth and effective field size for local hyperthermia," Progress In Electromagnetics Research B, Vol. 4, 273-283, 2008.
doi:10.2528/PIERB08011403

20. Gong, Y. and G. Wang, "Superficial tumor hyperthermia with flat left-handed metamaterial lens Progress In Electromagnetics Research ,", Vol. 98, 389-405, 2009.