書誌事項
- 公開日
- 2002-09-26
- 権利情報
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- http://onlinelibrary.wiley.com/termsAndConditions#vor
- DOI
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- 10.1002/mrm.10267
- 公開者
- Wiley
この論文をさがす
説明
<jats:title>Abstract</jats:title><jats:p>A regularized algorithm is presented for localized in vivo shimming. The technique uses first‐ (<jats:italic>X</jats:italic>,<jats:italic>Y</jats:italic>,<jats:italic>Z</jats:italic>), second‐ (<jats:italic>Z</jats:italic><jats:sup>2</jats:sup>, <jats:italic>ZX</jats:italic>, <jats:italic>ZY</jats:italic>, <jats:italic>X</jats:italic><jats:sup>2</jats:sup>‐<jats:italic>Y</jats:italic><jats:sup>2</jats:sup>, <jats:italic>XY</jats:italic>), and third‐order (<jats:italic>Z</jats:italic><jats:sup>3</jats:sup>) 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‐mean‐square (RMS) value of the <jats:italic>B</jats:italic><jats:sub>0</jats:sub> 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. Magn Reson Med 48:715–722, 2002. © 2002 Wiley‐Liss, Inc.</jats:p>
収録刊行物
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- Magnetic Resonance in Medicine
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Magnetic Resonance in Medicine 48 (4), 715-722, 2002-09-26
Wiley