Vafaeyan H, Ebrahimzadeh S A, Rahimian N, Alavijeh S Karimi, Madadi A, Faeghi F, Harirchian M H, Rad H Saligheh
Quantitative MR Imaging and Spectroscopy Group, Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences (TUMS), Tehran, Iran.
School of Para-Medicine, Shahid Beheshti University of Medical Science, Tehran, Iran.
Australas Phys Eng Sci Med. 2015 Dec;38(4):611-8. doi: 10.1007/s13246-015-0390-1. Epub 2015 Nov 2.
Proton magnetic resonance spectroscopic imaging ((1)H-MRSI) enables the quantification of metabolite concentration ratios in the brain. The major purpose of the current work is to characterize NAA/Cho, NAA/Cr and Myo/Cr in multiple sclerosis (MS) patients, and to estimate their reproducibility in healthy controls. Twelve MS patients and five healthy volunteers were imaged using (1)H-MRSI at 3T. Eddy current correction was performed using a single-voxel non-water suppressed acquisition on an external water phantom. Time-domain quantification was carried out using subtract-QUEST technique, and based on an optimal simulated metabolite database. Reproducibility was evaluated on the same quantified ratios in five normal subjects. An optimal database was created for the quantification of the MRSI data, consisting of choline (Cho), creatine (Cr), N-acetyl aspartate (NAA), lactate (Lac), lipids, myo-inositol (Myo) and glutamine + glutamate (Glx). Decreasing of NAA/Cr and NAA/Cho ratios, as well as an increase in Myo/Cr ratio were observed for MS patients in comparison with control group. Reproducibility of NAA/Cr, NAA/Cho and Myo/Cr in control group was 0.98, 0.87 and 0.64, respectively, expressed as the squared correlation coefficient R (2) between duplicate experiments. We showed that MRSI alongside the time-domain quantification of spectral ratios offers a sensitive and reproducible framework to differentiate MS patients from normals.
质子磁共振波谱成像（¹H-MRSI）能够对大脑中的代谢物浓度比进行定量分析。当前这项工作的主要目的是对多发性硬化症（MS）患者的NAA/Cho、NAA/Cr和Myo/Cr进行特征描述，并评估其在健康对照者中的可重复性。12例MS患者和5名健康志愿者在3T条件下接受¹H-MRSI成像。使用外部水模体上的单体素非水抑制采集进行涡流校正。采用减法QUEST技术并基于优化的模拟代谢物数据库进行时域定量分析。对5名正常受试者相同的定量比值进行可重复性评估。创建了一个用于MRSI数据定量分析的优化数据库，该数据库包含胆碱（Cho）、肌酸（Cr）、N-乙酰天门冬氨酸（NAA）、乳酸（Lac）、脂质、肌醇（Myo）和谷氨酰胺+谷氨酸（Glx）。与对照组相比，观察到MS患者的NAA/Cr和NAA/Cho比值降低，以及Myo/Cr比值升高。对照组中NAA/Cr、NAA/Cho和Myo/Cr的可重复性分别为0.98、0.87和0.64，以重复实验之间的平方相关系数R²表示。我们表明，MRSI结合谱比值的时域定量分析为区分MS患者和正常人提供了一个敏感且可重复的框架。
