UCL Institute of Neurology, Department of Neuroinflammation, NMR Research Unit, London, United Kingdom.
J Magn Reson Imaging. 2010 Nov;32(5):1054-60. doi: 10.1002/jmri.22381.
To investigate changes in magnetic resonance imaging (MRI) indices following formalin fixation of postmortem multiple sclerosis (MS) cortical gray matter (CGM). Postmortem MS brain is being used to establish pathological correlates of changes detected using MRI, with recent emphasis on CGM. Fixation induces tissue alterations that may confound inference of in vivo observations from MRI/histology correlation studies.
T(2)-weighted scans were obtained alongside quantitative T(1), magnetization transfer ratio (MTR), and macromolecular proton fraction (f(B)) measurements before and after formalin fixation of 15 postmortem brain samples. Type and size of CGM lesions (CGML) was identified on sections immunostained for myelin basic protein.
MRI indices obtained in unfixed MS CGM were similar to values obtained in subjects with MS in vivo. Fixation led to reduction in T(1) (617 msec [standard deviation = 114] vs. 1156 msec [216]) and MTR (24.1 [3.3] percent units [pu] vs. 29.1 [2.5] pu) and increase in f(B) (5.4 [0.7] pu vs. 3.2 [2.3] pu) (all P < 0.01). The proportion of CGM affected by demyelination did not alter the MRI data.
MRI indices in the CGM are significantly altered following tissue fixation.
研究福尔马林固定死后多发性硬化症（MS）皮质灰质（CGM）后磁共振成像（MRI）指标的变化。死后 MS 大脑正被用于建立使用 MRI 检测到的变化的病理相关性，最近强调了 CGM。固定会引起组织改变，这可能会混淆从 MRI/组织学相关性研究中推断体内观察结果。
在福尔马林固定 15 个死后脑样本之前和之后，获得 T2 加权扫描以及定量 T1、磁化转移率（MTR）和大分子质子分数（f（B））测量值。在免疫组织化学染色为髓鞘碱性蛋白的切片上识别 CGM 病变（CGML）的类型和大小。
未经固定的 MS CGM 中的 MRI 指数与体内 MS 患者获得的值相似。固定导致 T1 减少（617 msec [标准偏差 = 114] 与 1156 msec [216]）和 MTR（24.1 [3.3] 百分比单位 [pu] 与 29.1 [2.5] pu）以及 f（B）增加（5.4 [0.7] pu 与 3.2 [2.3] pu）（所有 P < 0.01）。脱髓鞘病变对 CGM 的影响比例并没有改变 MRI 数据。
组织固定后 CGM 中的 MRI 指数发生了显著变化。
