Abstract
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.
| Original language | English |
|---|---|
| Pages (from-to) | 715-722 |
| Number of pages | 8 |
| Journal | Magnetic Resonance in Medicine |
| Volume | 48 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - 2002 Oct 1 |
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All Science Journal Classification (ASJC) codes
- Radiology Nuclear Medicine and imaging
Cite this
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Regularized higher-order in vivo shimming. / Kim, Donghyun; Adalsteinsson, Elfar; Glover, Gary H.; Spielman, Daniel M.
In: Magnetic Resonance in Medicine, Vol. 48, No. 4, 01.10.2002, p. 715-722.Research output: Contribution to journal › Article
TY - JOUR
T1 - Regularized higher-order in vivo shimming
AU - Kim, Donghyun
AU - Adalsteinsson, Elfar
AU - Glover, Gary H.
AU - Spielman, Daniel M.
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
VL - 48
SP - 715
EP - 722
JO - Magnetic Resonance in Medicine
JF - Magnetic Resonance in Medicine
SN - 0740-3194
IS - 4
ER -