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Improved compression of SAR matrices by a reformulation of the generalized virtual observation point compression scheme
Vincent Gras1 and Nicolas Boulant1
1DRF/Joliot/Neurospin, CEA - Université Paris Saclay, Gif sur Yvette, France
he Virtual Observation Points compression problem is reformulated to further reduce by a factor ~5 the number of SAR matrices used for RF pulse design and exam supervision.
Number of VOPs computed for different overestimation factors λ. Blue: Lee’s generalized VOP compression method, red: this work.
10g-SAR computed over the uncompressed set of voxels and over the VOPs for the two different methods (λ=0.7) and for 1 million random RF shims. a) 10g-SAR over the VOPs versus the true SAR. The dashed black line is the identity line. b) Boxplots of the relative overestimation for the two methods. The SAR is never underestimated.