MR spectroscopic evaluation of N-acetylaspartate's T2 relaxation time and concentration corroborates white matter abnormalities in schizophrenia
MR spectroscopic evaluation of N-acetylaspartate's T2 relaxation time and concentration corroborates white matter abnormalities in schizophrenia
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DOI：
10.1016/j.neuroimage.2009.06.061
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发表时间：
2009-11-15
期刊：
影响因子：
5.7
通讯作者：
Ende, Gabriele
中科院分区：
文献类型：
--
作者：
Tunc-Skarka, Nuran;Weber-Fahr, Wolfgang;Ende, Gabriele
磁共振波谱可以对大脑生物化学的某些方面进行体内分析。精神分裂症关键区域的 N-乙酰天冬氨酸减少已被多次报道，但并非没有争议。我们的目的是调查在未校正个体 T2 弛豫时间（称为“表观 tNAA 浓度”）的情况下确定的 N-乙酰天冬氨酸浓度降低是否是由于绝对 N-乙酰天冬氨酸浓度降低或弛豫特性改变所致。为此，我们测量了绝对浓度，同时评估了各个 T2 弛豫时间。我们使用 3 T 磁共振扫描仪评估了 23 名符合 DSM-IV 精神分裂症标准的患者和 29 名年龄相似的健康对照受试者的额叶白质体素的代谢物浓度和代谢物/水弛豫时间。研究发现，精神分裂症患者组的 N-乙酰天冬氨酸浓度显着降低，N-乙酰天冬氨酸的 T2 弛豫时间也缩短。由于精神分裂症组中 N-乙酰天冬氨酸的 T2 降低，健康对照者和精神分裂症患者之间的明显 N-乙酰天冬氨酸浓度差异随着回波时间的增加而增加。对于任何其他代谢物浓度或代谢物/脑水弛豫时间，没有发现组间差异。 N-乙酰天冬氨酸减少以及 N-乙酰天冬氨酸 T2 弛豫时间缩短的这些发现为精神分裂症中白质微观结构的变化提供了进一步的证据。此外，他们还解释了为什么关于精神分裂症中 N-乙酰天冬氨酸浓度降低的报道并不总是得到证实。 (C) 2009 Elsevier Inc. 保留所有权利。
Magnetic resonance spectroscopy enables the in vivo analysis of certain aspects of brain biochemistry. Reduced N-acetylaspartate in key regions of schizophrenia has been reported repeatedly but not without controversy. Our objective is to investigate whether reduced N-acetylaspartate concentrations determined without correction for individual T2 relaxation time (referred to as 'apparent tNAA concentration') are due to a reduced absolute N-acetylaspartate concentration or to altered relaxation properties. For this purpose we measured absolute concentrations while evaluating individual T2 relaxation times. We evaluated the metabolite concentrations and metabolite/water relaxation times of a frontal white matter voxel from 23 patients who met DSM-IV criteria for schizophrenia and 29 healthy control subjects with similar age at a 3 T magnetic resonance scanner. A significantly reduced N-acetylaspartate concentration as well as shortened N-acetylaspartate's T2 relaxation time in the schizophrenic patient group was found. The apparent N-acetylaspartate concentration difference between healthy controls and patients with schizophrenia increased with the echo time due to a decreased N-acetylaspartate's T2 in the schizophrenic group. No group difference was found for any other metabolite concentration or metabolite/brain water relaxation time. These findings of reduced N-acetylaspartate as well as shortened N-acetylaspartate's T2 relaxation time give further evidence for microstructural white matter changes in schizophrenia. Furthermore, they elucidate why reports of a reduced N-acetylaspartate concentration in schizophrenia were not always corroborated. (C) 2009 Elsevier Inc. All rights reserved.