B0magnetic field homogeneity and shimming for in vivo magnetic resonance spectroscopy.
The homogenization of B0conditions is necessary for every magnetic resonance spectroscopy (MRS) investigation. Its direct consequence is narrow spectral lines, on which reliable separation and quantification of biochemicals, and thus experimentally obtainable metabolic information, fundamentally relies. Besides spectral linewidth, unwanted B0inhomogeneity also impairs other aspects of the MRS experiment, such as water suppression and editing efficiency, that rely on exact frequency definition. Therefore, experimental B0homogenization, called B0shimming, is mandatory for meaningful MRS, and high-level B0shimming is arguably one of the most important ingredients for successful MRS investigations. In this review, we describe the relevance of B0homogeneity for in vivo MRS and summarize common concepts and specific solutions for its experimental optimization.
Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT 06520, USA; Department of Neurology, Yale University School of Medicine, New Haven, CT 06520, USA. Electronic address: christoph.juchem@yale.edu.
Christoph
C
Juchem
Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT 06520, USA; Department of Biomedical Engineering, Yale University, New Haven, CT 06520, USA.
Robin A
RA
de Graaf
D000818:Animals; D006801:Humans; D060526:Magnetic Fields; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*
B(0) field modeling; B(0) homogeneity; B­(0) shimming; DYNAMITE; FASTMAP; Spherical harmonic functions