Magnetic resonance spectroscopy of rat kidney in vivo at 9.4 T

Abstract

Glutamate (Glu), glutamine (Gln), myo-insotol (Ins), taurine (Tau), choline (Cho), and betaine (Bet) are kidney metabolites whose levels are relevant to the study of Renal Cell Carcinoma (RCC). The presented work investigates the quantification of Glx (Glu + Gln), Ins, and Tau, relative to Cho + Bet with magnetic resonance spectroscopy (MRS) in rat kidney at 9.4 T. The Point-Resolved Spectroscopy (PRESS) pulse sequence was employed for non-invasive MRS acquisition in vivo from the right kidney of four rats. LCModel was utilized for peak fitting and spectral analysis of the in-vivo spectra. Relative metabolite concentrations and LCModel Cramér-Rao Lower Bounds (CRLBs) are reported. Relative metabolite concentrations are reported because the absolute concentration of any metabolite is unknown. The concentrations of Glx, Ins, and Tau, relative to Cho + Bet, the largest peak, were found to be, on average, 2.16, 1.40, and 2.17, with average CRLB values of 12.5%, 12.8%, and 16.8%, respectively. The average CRLB of Cho + Bet was 4.8%. To our knowledge, this is the first non-invasive MRS study of rat kidney.