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An investigation into the dependence of virtual observation point-based specific absorption rate calculation complexity on number of channels.
- Source :
-
Magnetic resonance in medicine [Magn Reson Med] 2023 Jan; Vol. 89 (1), pp. 469-476. Date of Electronic Publication: 2022 Sep 11. - Publication Year :
- 2023
-
Abstract
- Purpose: This study aims to find a relation between the number of channels and the computational burden for specific absorption rate (SAR) calculation using virtual observation point-based SAR compression.<br />Methods: Eleven different arrays of rectangular loops covering a cylinder of fixed size around the head of an anatomically correct voxel model were simulated. The resulting Q-matrices were compressed with 2 different compression algorithms, with the overestimation fixed to a certain fraction of worst-case SAR, median SAR, or minimum SAR. The latter 2 were calculated from 1e6 normalized random excitation vectors.<br />Results: The number of virtual observation points increased with the number of channels to the power of 2.3-3.7, depending on the compression algorithm when holding the relative error fixed. Together with the increase in the size of the Q-matrices (and therefore the size of the virtual observation points), the total increase in computational burden with the number of channels was to the power of 4.3-5.7.<br />Conclusion: The computational cost emphasizes the need to use the best possible compression algorithms when moving to high channel counts.<br /> (© 2022 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals LLC on behalf of International Society for Magnetic Resonance in Medicine.)
Details
- Language :
- English
- ISSN :
- 1522-2594
- Volume :
- 89
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Magnetic resonance in medicine
- Publication Type :
- Academic Journal
- Accession number :
- 36089826
- Full Text :
- https://doi.org/10.1002/mrm.29434