Laule Cornelia, Vavasour Irene M, Whittall Kenneth P, Oger Joel, Paty Donald W, Li David K B, MacKay Alex L, Arnold Douglas L
Dept. of Physics & Astronomy, University of British Columbia, 2211 Wesbrook Mall, Vancouver BC, V6T 2B5, Canada.
J Neurol. 2003 Aug;250(8):924-31. doi: 10.1007/s00415-003-1115-z.
Magnetisation transfer (MT) imaging provides indirect information on tissue structure abnormalities in areas that otherwise may appear normal on conventional MRI. We determined the evolution of MT changes in normal appearing white matter (NAWM) and lesion on serial examination of 9 multiple sclerosis (MS) patients and age matched controls. The mean NAWM MT ratio (MTR) was found to correlate strongly (R = 0.93) with the length of time since the patient's first clinical presentation and was well characterized by a linear decrease of -0.16%/year (p < 0.0001). The time zero intercept of the NAWM MTR regression was 30.7 +/- 0.2%, not different from the average MTR of white matter from controls (30.4 +/- 0.2 %). An additional gradual decrease in NAWM MTR was observed 6 to 12 months before the appearance of a new lesion on conventional MRI, while a more precipitous decrease in MTR was seen 2 to 6 months before the lesion appeared. Those lesions that exhibited pre-lesion MTR decreases showed less MTR recovery than lesions which had no pre-lesion MTR decrease. The data suggest that the MTR of NAWM in MS undergoes a slow progressive decrease that starts at disease onset and accelerates rapidly in focal areas just prior to lesion appearance on conventional MRI.
磁化传递（MT）成像可提供有关组织结构异常的间接信息，这些区域在传统MRI上可能看似正常。我们对9例多发性硬化症（MS）患者和年龄匹配的对照者进行了系列检查，以确定正常外观白质（NAWM）和病变中MT变化的演变情况。发现平均NAWM MT比率（MTR）与患者首次临床表现后的时间长度密切相关（R = 0.93），其特征为以每年-0.16%的线性下降（p < 0.0001）。NAWM MTR回归的时间零点截距为30.7 +/- 0.2%，与对照组白质的平均MTR（30.4 +/- 0.2%）无差异。在传统MRI上出现新病变前6至12个月，观察到NAWM MTR有额外的逐渐下降，而在病变出现前2至6个月，MTR下降更为急剧。那些在病变前MTR下降的病变，其MTR恢复程度低于无病变前MTR下降的病变。数据表明，MS中NAWM的MTR从疾病发作开始经历缓慢的渐进性下降，并在传统MRI上病变出现前的局部区域迅速加速。
