Neema Mohit, Goldberg-Zimring Daniel, Guss Zachary D, Healy Brian C, Guttmann Charles R G, Houtchens Maria K, Weiner Howard L, Horsfield Mark A, Hackney David B, Alsop David C, Bakshi Rohit
Department of Neurology, Brigham and Women's Hospital, Laboratory for Neuroimaging Research, Partners MS Center, Harvard Medical School, Boston, MA 02445, USA.
Neuroimage. 2009 Jul 1;46(3):633-41. doi: 10.1016/j.neuroimage.2009.03.001. Epub 2009 Mar 10.
MRI at 3 T has increased sensitivity in detecting overt multiple sclerosis (MS) brain lesions; a growing body of data suggests clinically relevant damage occurs in the normal-appearing white matter (NAWM). We tested a novel pulse sequence to determine whether 3 T MRI spin-spin relaxometry detected damage in NAWM of MS patients (n=13) vs. age-matched normal controls [(NL) (n=11)]. Baseline characteristics of the MS group were: age (mean+/-SD) 42.5+/-5.4 (range 33-51 years), disease duration 9.0+/-6.4 (range 1-22 years), Expanded Disability Status Scale score 2.5+/-1.7 (range 1-6.5). Brain MRI measures, obtained at 3 T, included global and regional NAWM transverse relaxation rate [R2 (=1/T2)], derived from 3D fast spin-echo T2 prepared images, and global white matter volume fraction derived from SPGR images. The regional NAWM areas investigated were the frontal lobe, parietal lobe, and the genu and splenium of the corpus callosum. Mean NAWM R2 was lower (indicating T2 prolongation) in MS than NL in the whole brain (p=0.00047), frontal NAWM (p=0.00015), parietal NAWM (p=0.0069) and callosal genu (p=0.0019). Similarly, R2 histogram peak position was lower in NAWM in MS than NL in the whole brain (p=0.019). However, the normalized WM volume fractions were similar in both MS and NL (p>0.1). This pilot study suggests that a novel 3D fast spin-echo pulse sequence at 3 T, used to derive R2 relaxation maps, can detect tissue damage in the global and regional cerebral NAWM of MS patients that is missed by conventional lesion and atrophy measures. Such findings may represent demyelination, inflammation, glial proliferation and axonal loss.
3T磁共振成像（MRI）在检测明显的多发性硬化（MS）脑损伤方面具有更高的敏感性；越来越多的数据表明，在外观正常的白质（NAWM）中会出现具有临床意义的损伤。我们测试了一种新型脉冲序列，以确定3T MRI自旋-自旋弛豫测量法能否检测出MS患者（n = 13）与年龄匹配的正常对照者[（NL）（n = 11）]的NAWM中的损伤。MS组的基线特征为：年龄（平均值±标准差）42.5±5.4（范围33 - 51岁），病程9.0±6.4（范围1 - 22年），扩展残疾状态量表评分2.5±1.7（范围1 - 6.5）。在3T下获得的脑MRI测量指标包括：从3D快速自旋回波T2准备图像得出的全脑和局部NAWM横向弛豫率[R2（=1/T2）]，以及从扰相梯度回波（SPGR）图像得出的全脑白质体积分数。所研究的局部NAWM区域为额叶、顶叶以及胼胝体的膝部和压部。在全脑（p = 0.00047）、额叶NAWM（p = 0.00015）、顶叶NAWM（p = 0.0069）和胼胝体膝部（p = 0.0019）中，MS患者的平均NAWM R2较低（表明T2延长），低于NL组。同样，在全脑中，MS患者NAWM的R2直方图峰值位置低于NL组（p = 0.019）。然而，MS组和NL组的标准化白质体积分数相似（p>0.1）。这项初步研究表明，用于得出R2弛豫图的新型3T 3D快速自旋回波脉冲序列能够检测出MS患者全脑和局部脑NAWM中的组织损伤，而这些损伤是传统的损伤和萎缩测量方法所遗漏的。这些发现可能代表脱髓鞘、炎症、胶质细胞增生和轴突损失。
