TY  - JOUR
AU  - Orzada, Stephan
AU  - Fiedler, Thomas M
AU  - Kesting, Jan
AU  - Hubmann, Max Joris
AU  - Ladd, Mark
TI  - On the measurement errors in SAR supervision introduced by directional couplers.
JO  - Magnetic resonance materials in physics, biology and medicine
VL  - nn
SN  - 0968-5243
CY  - Heidelberg
PB  - Springer
M1  - DKFZ-2025-01623
SP  - nn
PY  - 2025
N1  - #EA:E020#LA:E020# / epub
AB  - This study proposes a framework for determining the calculation error in online SAR supervision introduced by directional couplers.A mathematical framework is introduced showing how the error in the measured excitation vector compared to the actual excitation vector can be rewritten as a new set of virtual observation points (VOPs). By comparing the new set of VOPs to the original VOPs through an optimization, the maximum underestimation of SAR can be calculated. The framework is then applied to five different RF arrays.The results show that the error in SAR calculation is very dependent on the position of the reference plane of the directional coupler measurements and the S-parameters of the array. To have an error of less than 5
KW  - Directional couplers (Other)
KW  - MRI (Other)
KW  - Measurement error (Other)
KW  - SAR (Other)
KW  - Virtual observation points (Other)
KW  - pTx (Other)
LB  - PUB:(DE-HGF)16
C6  - pmid:40759812
DO  - DOI:10.1007/s10334-025-01287-7
UR  - https://inrepo02.dkfz.de/record/303374
ER  -