Peng Xi, Nguyen Hien, Haldar Justin, Hernando Diego, Wang Xian-Pei, Liang Zhi-Pei
School of Electronic Information, Wuhan University, 430079, China.
Annu Int Conf IEEE Eng Med Biol Soc. 2010;2010:883-6. doi: 10.1109/IEMBS.2010.5627873.
Magnetic field inhomogeneity is a long-standing problem in magnetic resonance imaging (MRI) and spectroscopic imaging (MRSI). Specifically, in MRSI, field inhomogeneity, if not corrected, can cause frequency shifts, line broadening, and lineshape distortions in the spectral peaks. This paper addresses the problem of correcting the field inhomogeneity effects on limited k-space MRSI data. A penalized maximum-likelihood method is proposed, which enables the use of anatomical constraints for improving the correction performance with only limited k-space data. Simulation results are shown to demonstrate the effectiveness of the proposed method.
磁场不均匀性是磁共振成像（MRI）和磁共振波谱成像（MRSI）中长期存在的问题。具体而言，在MRSI中，如果不校正，磁场不均匀性会导致光谱峰出现频率偏移、线宽展宽和线形畸变。本文解决了校正磁场不均匀性对有限k空间MRSI数据影响的问题。提出了一种惩罚最大似然方法，该方法能够利用解剖学约束，仅通过有限的k空间数据来提高校正性能。仿真结果表明了所提方法的有效性。
