In vitro absolute metabolic quantification by magnetic resonance spectroscopy

In this project we estimated characteristic nuclear relaxation times (T1 and T2) from 1H in vitro of water and the following human brain metabolites: N-Acetyl-Aspartate (NAA), Choline (Cho), Creatine (Cr) and Myo-Inositol (M-Ins) using nuclear magnetic resonance spectroscopy, aiming at relaxation effects correction for absolute quantification. Phantoms with 300 mL of a standard solution with a metabolite were used for spectra acquisition. Variable eco time sequences were used to determinate T2 while variable repetition or inversion time was used for T1 determination. Spectra processing was done with MRUI and LCModel software. Origin 8.0 was used for data fitting. The following T1/T2 values (ms) were the best estimated according to calculated absolute concentration analyses: (4061/934) for water, (1800/830) for NAA, (2316/717) for Cr, (2356/1095) for Cho and (1537/531) for M-Ins. With MRUI better results were obtained in T1 and T2 determination for relaxation effects correction in the absolute quantification process. (author)