van Walderveen M A, Barkhof F, Pouwels P J, van Schijndel R A, Polman C H, Castelijns J A
MR Centre for MS Research and Department of Radiology, University Hospital Vrije Universiteit, Amsterdam, The Netherlands.
Ann Neurol. 1999 Jul;46(1):79-87. doi: 10.1002/1531-8249(199907)46:1<79::aid-ana12>3.3.co;2-0.
Hypointense T1 lesions in multiple sclerosis patients correlate with axonal loss at autopsy and biopsy. We evaluated the chemical substrate of hypointense T1 lesions by using in vivo proton magnetic resonance spectroscopy, and analyzed the spectroscopic correlate of increased T1-relaxation time measurements. Localized proton magnetic resonance spectroscopy and T1-relaxation time measurements were performed in lesions, selected on T1-weighted spin-echo magnetic resonance images according to degree of hypointensity, in normal appearing white matter (NAWM) and in normal white matter of controls. In NAWM, prolongation of T1-relaxation time and a decrease in N-acetylaspartate (NAA) were present, compared with normal white matter. Severely hypointense lesions showed a lower concentration of NAA and creatine compared with NAWM and a lower concentration of NAA compared with isointense to mildly hypointense lesions. NAA concentration correlated with degree of hypointensity of lesions and with T1-relaxation time within the spectroscopic voxel. Our results provide the first in vivo evidence of axonal damage in severely hypointense T1 lesions in multiple sclerosis patients. T1-relaxation time correlates with the concentration of NAA in both multiple sclerosis lesions and NAWM, indicating that this parameter deserves further evaluation to monitor disease progression.
多发性硬化症患者的T1低信号病灶与尸检和活检时的轴突损失相关。我们通过体内质子磁共振波谱评估了T1低信号病灶的化学底物，并分析了T1弛豫时间测量增加的波谱相关性。在根据T1加权自旋回波磁共振图像上的低信号程度选择的病灶、正常表现白质（NAWM）以及对照组的正常白质中进行了局部质子磁共振波谱和T1弛豫时间测量。与正常白质相比，NAWM中T1弛豫时间延长且N-乙酰天门冬氨酸（NAA）减少。与NAWM相比，严重低信号病灶显示NAA和肌酸浓度较低，与等信号至轻度低信号病灶相比，NAA浓度较低。NAA浓度与病灶的低信号程度以及波谱体素内的T1弛豫时间相关。我们的结果提供了多发性硬化症患者严重低信号T1病灶中轴突损伤的首个体内证据。T1弛豫时间与多发性硬化症病灶和NAWM中的NAA浓度相关，表明该参数值得进一步评估以监测疾病进展。
