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Spatial resolution of numerical models of man and calculated specific absorption rate using the FDTD method: A study at 64 MHz in a magnetic resonance imaging coil
Author(s) -
Collins Christopher M.,
Smith Michael B.
Publication year - 2003
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.10359
Subject(s) - finite difference time domain method , specific absorption rate , image resolution , resolution (logic) , electromagnetic coil , magnetic resonance imaging , nuclear magnetic resonance , absorption (acoustics) , radiofrequency coil , computational physics , materials science , physics , optics , acoustics , computer science , radiology , medicine , telecommunications , quantum mechanics , artificial intelligence , antenna (radio)
Purpose To examine how fine a model resolution is necessary for calculation of specific energy absorption rate (SAR) for the human head in regions as small as 1 g. Materials and Methods Here we perform a simple study comparing the maximum SAR averaged over any 1 cm 3 and SAR averaged over the entire head for several models of the same human head within the same radiofrequency coil, but with spatial resolutions varying from 8–100 Yee cells per cm 3 . Results Over the range of model resolutions from 8–100 Yee cells per cm 3 , there is only a 16% variation in maximum SAR in any 1 cm 3 of tissue in the head, and only a 7% variation in SAR averaged over the entire head. Conclusion While it is always desirable to perform SAR calculations with the greatest possible accuracy, in calculations of the maximum SAR levels in any 1 cm 3 of tissue, spatial resolutions greater than 5 mm may not yield notably different results than those with a spatial resolution of 5 mm. J. Magn. Reson. Imaging 2003;18:383–388. © 2003 Wiley‐Liss, Inc.