TY - JOUR
T1 - Regularized higher-order in vivo shimming
AU - Kim, Dong Hyun
AU - Adalsteinsson, Elfar
AU - Glover, Gary H.
AU - Spielman, Daniel M.
N1 - Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2002/10/1
Y1 - 2002/10/1
N2 - A regularized algorithm is presented for localized in vivo shimming. The technique uses first- (X,Y,Z), second- (Z2, ZX, ZY, X2-Y2, XY), and third-order (Z3) shim coils, and is robust when applied to arbitrarily-shaped, as well as off-center, regions of interest (ROIs). A single-shot spiral pulse sequence is used for rapid field map acquisition, and a least-squares calculation of the shim currents is performed to minimize the root-meansquare (RMS) value of the B0 inhomogeneity over a user-selected ROI. The use of a singular value decomposition (SVD) in combination with a regularization algorithm significantly improves the numerical stability of the least-squares fitting procedure. The fully automated shimming package is implemented on a 3 T GE Signa system and its robust performance is demonstrated in phantom and in vivo studies.
AB - A regularized algorithm is presented for localized in vivo shimming. The technique uses first- (X,Y,Z), second- (Z2, ZX, ZY, X2-Y2, XY), and third-order (Z3) shim coils, and is robust when applied to arbitrarily-shaped, as well as off-center, regions of interest (ROIs). A single-shot spiral pulse sequence is used for rapid field map acquisition, and a least-squares calculation of the shim currents is performed to minimize the root-meansquare (RMS) value of the B0 inhomogeneity over a user-selected ROI. The use of a singular value decomposition (SVD) in combination with a regularization algorithm significantly improves the numerical stability of the least-squares fitting procedure. The fully automated shimming package is implemented on a 3 T GE Signa system and its robust performance is demonstrated in phantom and in vivo studies.
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U2 - 10.1002/mrm.10267
DO - 10.1002/mrm.10267
M3 - Article
C2 - 12353290
AN - SCOPUS:0036787384
VL - 48
SP - 715
EP - 722
JO - Magnetic Resonance in Medicine
JF - Magnetic Resonance in Medicine
SN - 0740-3194
IS - 4
ER -