Cross-sectional and longitudinal reproducibility of rhesus macaque brain metabolites: A proton MR spectroscopy study at 3 T
✍ Scribed by William E. Wu; Ivan I. Kirov; Ke Zhang; James S. Babb; Chan-Gyu Joo; Eva-Maria Ratai; R. Gilberto González; Oded Gonen
- Publisher
- John Wiley and Sons
- Year
- 2011
- Tongue
- English
- Weight
- 662 KB
- Volume
- 65
- Category
- Article
- ISSN
- 0740-3194
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Non‐human primates are often used as preclinical model systems for (mostly diffuse or multi‐focal) neurological disorders and their experimental treatment. Due to cost considerations, such studies frequently utilize non‐destructive imaging modalities, MRI and proton MR spectroscopy (^1^H MRS). Cost may explain why the inter‐ and intra‐animal reproducibility of the ^1^H MRS observed brain metabolites, are not reported. To this end, we performed test‐retest three‐dimensional brain ^1^H MRS in five healthy rhesus macaques at 3 T. Spectra were acquired from 224 isotropic (0.5 cm)^3^ = 125 μL voxels, over 28 cm^3^ (∼35%) of the brain, then individually phased, frequency aligned and summed into a spectrum representative of the entire volume of interest. This dramatically increases the metabolites' signal‐to‐noise ratios, while maintaining the (narrow) voxel linewidth. The results show that the average N‐acetylaspartate, creatine, choline, and myo‐inositol concentrations in the macaque brain are: 7.7 ± 0.5, 7.0 ± 0.5, 1.2 ± 0.1 and 4.0 ± 0.6 mM/g wet weight (mean ± standard deviation). Their inter‐animal coefficients of variation (CV) are 4%, 4%, 6%, and 15%; and the longitudinal (intra‐animal) CVs are lower still: 4%, 5%, 5%, and 4%, much better than the 22%, 33%, 36%, and 45% intra‐voxel CVs, demonstrating the advantage of the approach and its utility for preclinical studies of diffuse neurological diseases in rhesus macaques. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.