Short TE Volumetric Spiral 1H MR Spectroscopic Imaging of the Human Brain at 3T using semi-LASER

Introduction Proton MR chemical shift imaging (CSI) of brain metabolites can identify biomarkers relevant to healthy or metabolic cerebral metabolism. At short TE, strongly J-coupled and short T2 metabolites can be detected. High field offers higher SNR and improved spectral resolution with the disadvantage of increased B1 and B0 heterogeneities as well as chemical shift displacement error (CSDE). The semi-LASER (Localisation with Adiabatic SElective Refocusing) sequence reduces CSDE and B1 heterogeneity effects with improved slice selection profiles [1]. Phase encoding CSI [2] has long acquisition time which depends on spatial resolution. Spiral Spectroscopic Imaging (SSI) by simultaneous spatial and spectral encodings reduces minimum acquisition time [3]. It thus becomes possible to acquire additional data such as a spatial dimension and/or a second spectral dimension. We present here volumetric SSI of the human brain with a 32 ms TE using slice selective adiabatic refocusing pulses.