Department of Psychology, University of Alabama at Birmingham, Alabama, US.
Department of Neurosurgery and Core for Advanced MRI, Baylor College of Medicine, Houston, Texas, US.
NMR Biomed. 2020 Jul;33(7):e4313. doi: 10.1002/nbm.4313. Epub 2020 Apr 29.
Assessing brain temperature can provide important information about disease processes (e.g., stroke, trauma) and therapeutic effects (e.g., cerebral hypothermia treatment). Whole-brain magnetic resonance spectroscopic imaging (WB-MRSI) is increasingly used to quantify brain metabolites across the entire brain. However, its feasibility and reliability for estimating brain temperature needs further validation. Therefore, the present study evaluates the reproducibility of WB-MRSI for temperature mapping as well as metabolite quantification across the whole brain in healthy volunteers. Ten healthy adults were scanned on three occasions 1 week apart. Brain temperature, along with four commonly assessed brain metabolites-total N-acetyl-aspartate (tNAA), total creatine (tCr), total choline (tCho) and myo-inositol (mI)-were measured from WB-MRSI data. Reproducibility was evaluated using the coefficient of variation (CV). The measured mean (range) of the intra-subject CVs was 0.9% (0.6%-1.6%) for brain temperature mapping, and 4.7% (2.5%-15.7%), 6.4% (2.4%-18.9%) and 14.2% (4.4%-52.6%) for tNAA, tCho and mI, respectively, with reference to tCr. Consistently larger variability was found when using H O as the reference for metabolite quantifications: 7.8% (3.3%-17.8%), 7.8% (3.1%-18.0%), 9.8% (3.7%-31.0%) and 17.0% (5.9%-54.0%) for tNAA, tCr, tCho and mI, respectively. Further, the larger the brain region (indicated by a greater number of voxels within that region), the better the reproducibility for both temperature and metabolite estimates. Our results demonstrate good reproducibility of whole-brain temperature and metabolite measurements using the WB-MRSI technique.
评估脑温可以提供有关疾病过程（例如中风、创伤）和治疗效果（例如脑低温治疗）的重要信息。全脑磁共振波谱成像（WB-MRSI）越来越多地用于定量整个大脑中的脑代谢物。然而，其用于估计脑温的可行性和可靠性需要进一步验证。因此，本研究评估了 WB-MRSI 技术在健康志愿者中进行全脑温度映射和代谢物定量的可重复性。10 名健康成年人在 1 周内进行了 3 次扫描。从 WB-MRSI 数据中测量脑温以及 4 种常见的脑代谢物-总 N-乙酰天冬氨酸（tNAA）、总肌酸（tCr）、总胆碱（tCho）和肌醇（mI）。使用变异系数（CV）评估重复性。脑温测量的个体内 CV 的平均（范围）为 0.9%（0.6%-1.6%），tNAA、tCho 和 mI 的 CV 分别为 4.7%（2.5%-15.7%）、6.4%（2.4%-18.9%）和 14.2%（4.4%-52.6%），以 tCr 为参照。当使用 H2O 作为代谢物定量的参照时，发现一致性更大的变异性：tNAA、tCr、tCho 和 mI 的 CV 分别为 7.8%（3.3%-17.8%）、7.8%（3.1%-18.0%）、9.8%（3.7%-31.0%）和 17.0%（5.9%-54.0%）。此外，脑区越大（该区域内的体素数量越多），温度和代谢物估计的可重复性越好。我们的结果表明，使用 WB-MRSI 技术进行全脑温度和代谢物测量具有良好的可重复性。
