Brooks W M, Friedman S D, Stidley C A
Center for Non-Invasive Diagnosis, University of New Mexico Health Science Center, Albuquerque 87131, USA.
Magn Reson Med. 1999 Jan;41(1):193-7. doi: 10.1002/(sici)1522-2594(199901)41:1<193::aid-mrm27>3.0.co;2-p.
The current study sought to investigate the reproducibility of a quantitative spectroscopic examination, using rigorous positioning guidelines and automated spectral fitting for measuring the cerebral metabolites N-acetylaspartate (NAA), creatine (Cre), choline (Cho), and myo-inositol (ml). Ten subjects were studied in three sessions to determine the variability associated with measurement of metabolites in normal-appearing occipitoparietal white matter, using short echo STEAM spectroscopy. A careful relocalization protocol based on local landmarks identified on thin-slice images was used. No changes in mean metabolite concentrations for each subject between sessions were found, confirming relocalization. Mean coefficients of variation in measurement of NAA, Cre, Cho, and ml were 3.30, 4.33, 5.30, and 8.10, respectively. These data suggest that changes in metabolite concentrations as small as 12% can be confidently discerned in an individual subject over time. The implication of these results to study design is discussed.
本研究旨在使用严格的定位指南和自动光谱拟合来测量脑代谢物N-乙酰天门冬氨酸（NAA）、肌酸（Cre）、胆碱（Cho）和肌醇（ml），以调查定量光谱检查的可重复性。使用短回波STEAM光谱法，对10名受试者进行了三次检查，以确定在正常枕顶叶白质中测量代谢物时的变异性。采用了基于薄层图像上识别出的局部标志物的仔细重新定位方案。未发现各受试者各次检查之间平均代谢物浓度有变化，证实了重新定位。NAA、Cre、Cho和ml测量的平均变异系数分别为3.30、4.33、5.30和8.10。这些数据表明，随着时间推移，个体受试者中低至12%的代谢物浓度变化都能被可靠地识别出来。讨论了这些结果对研究设计的意义。
