Department of Biomedical Engineering, University of Alberta, 1098 RTF, Edmonton, AB, Canada T6G 2V2.
Radiology. 2013 May;267(2):531-42. doi: 10.1148/radiol.12120863. Epub 2013 Jan 7.
To investigate the relationship between iron staining and magnetic resonance (MR) imaging measurements in postmortem subjects with multiple sclerosis (MS).
Institutional ethical approval was obtained, and informed consent was obtained from the subjects and/or their families. Four MR imaging methods based on transverse relaxation (T2 weighting, R2 mapping, and R2* mapping) and phase imaging were performed by using a 4.7-T system in three in situ postmortem patients with MS less than 28 hours after death and in one in vivo patient 1 year before death. Iron staining with the Perls iron reaction was performed after brain extraction. Region-of-interest measurements from six subcortical gray matter structures were obtained from MR imaging and then correlated with corresponding locations on photographs of iron-stained pathologic slices by using a separate linear least-squares regression in each subject. Iron status of white matter lesions, as determined by staining, was compared with appearance on MR images.
R2* mapping had the highest intrasubject correlations with iron in subcortical gray matter (R(2) = 0.857, 0.628, and 0.685; all P < .001), while R2 mapping (R(2) = 0.807, 0.615, 0.628, and 0.489; P < .001 and P = .001, .034, and .001, respectively), phase imaging (R(2) = 0.672, 0.441, 0.596, 0.548; all P ≤ .001), and T2-weighted imaging (R(2) = 0.463, 0.582, 0.650, and 0.551; all P < .001) had lower but still strong correlations. Within lesions, hypointense areas on phase images did not always represent iron. A hyperintense rim surrounding lesions on R2* maps was only present with iron staining, yet not all iron-staining lesions had R2* rim hyperintensity.
All four MR imaging methods had significant linear correlations with iron and could potentially be used to determine iron status of subcortical gray matter structures in MS, with R2* mapping being preferred. A reliable method of determining iron status within MS lesions was not established.
研究死后多发性硬化（MS）患者铁染色与磁共振（MR）成像测量值之间的关系。
本研究获得了机构伦理委员会的批准，并获得了受试者和/或其家属的知情同意。在 3 例死后 28 小时内的原位 MS 患者和 1 例生前 1 年的患者中，使用 4.7T 系统进行了 4 种基于横向弛豫（T2 加权、R2 映射和 R2*映射）和相位成像的 MR 成像方法。在提取大脑后，用 Perls 铁反应进行铁染色。从 6 个皮质下灰质结构的 MR 成像中获得感兴趣区测量值，然后通过在每个受试者中单独进行线性最小二乘回归，将其与铁染色病理切片照片上的相应位置相关联。通过染色确定的白质病变的铁状态与 MR 图像上的表现进行比较。
R2映射与皮质下灰质中的铁具有最高的受试者内相关性（R²=0.857、0.628 和 0.685；均 P＜0.001），而 R2 映射（R²=0.807、0.615、0.628 和 0.489；均 P＜0.001 和 P=0.001、0.034 和 0.001）、相位成像（R²=0.672、0.441、0.596、0.548；均 P≤0.001）和 T2 加权成像（R²=0.463、0.582、0.650 和 0.551；均 P＜0.001）具有较低但仍较强的相关性。在病变内，相位图像上的低信号区并不总是代表铁。R2图上病变周围的高信号环仅在铁染色时出现，但并非所有铁染色病变都有 R2*环高信号。
所有 4 种 MR 成像方法与铁均具有显著的线性相关性，可潜在用于确定 MS 皮质下灰质结构的铁状态，其中 R2*映射更优。尚未建立确定 MS 病变内铁状态的可靠方法。
