Department of Radiology, University of Calgary, Calgary, Alberta; Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta; Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta.
Ann Neurol. 2013 Jul;74(1):91-9. doi: 10.1002/ana.23867. Epub 2013 Aug 12.
To analyze the texture of T2-weighted magnetic resonance imaging (MRI) of postmortem multiple sclerosis (MS) brain, and to determine whether and how MRI texture correlates with tissue pathology.
Ten brain samples from 3 subjects with MS were examined. Areas of complete, partial, or no loss of Luxol fast blue (myelin) and Bielschowsky (axons) staining were marked on histological images, and matched on corresponding MRI as lesions, diffusely abnormal white matter (DAWM), and normal-appearing white matter (NAWM). The number of CD45(+) cells (inflammation) was also counted. MRI texture was computed using polar Stockwell transform and compared to histology.
Thirty-four lesions, 17 DAWM regions, and 36 NAWM regions were identified. After mixed effects modeling, MRI texture heterogeneity was greater in lesions than in DAWM (p < 0.001) and NAWM (p < 0.001), and was greater in DAWM than in NAWM (p < 0.001); the number of CD45+ cells was greater in both lesions (p < 0.001) and DAWM (p = 0.005) than in NAWM. In MRI, a gradient of texture heterogeneity was detected in lesions, with gradual tapering toward perilesional NAWM. Moreover, besides univariate correlation with histological markers, texture heterogeneity correlated independently with normalized myelin density (p < 0.01) when random effects were considered. Within sample, MRI texture correlated with myelin and axonal density in 7 of 10 samples (p < 0.01).
Texture analysis performed on routine clinical magnetic resonance images may be a potential measure of tissue integrity. Tissues with more severe myelin and axonal pathology are associated with greater texture heterogeneity.
分析死后多发性硬化症（MS）脑的 T2 加权磁共振成像（MRI）纹理，并确定 MRI 纹理是否以及如何与组织病理学相关。
对 3 名 MS 患者的 10 个脑样本进行检查。在组织学图像上标记完全、部分或无卢索快速蓝（髓鞘）和比尔斯沃斯基（轴突）染色的区域，并在相应的 MRI 上标记为病变、弥漫性异常白质（DAWM）和正常外观的白质（NAWM）。还计算了 CD45(+)细胞（炎症）的数量。使用极斯托克韦尔变换计算 MRI 纹理，并与组织学进行比较。
共识别出 34 个病变、17 个 DAWM 区域和 36 个 NAWM 区域。经过混合效应模型分析，病变的 MRI 纹理异质性大于 DAWM（p<0.001）和 NAWM（p<0.001），而 DAWM 则大于 NAWM（p<0.001）；病变和 DAWM 中的 CD45+细胞数量均多于 NAWM（p<0.001）。MRI 中，病变的纹理异质性呈梯度变化，逐渐向病变周围的 NAWM 变细。此外，除了与组织学标志物的单变量相关性外，当考虑随机效应时，纹理异质性与归一化髓鞘密度独立相关（p<0.01）。在样本内，7 个样本（p<0.01）的 MRI 纹理与髓鞘和轴突密度相关。
对常规临床磁共振图像进行纹理分析可能是一种潜在的组织完整性测量方法。组织病理学上更严重的髓鞘和轴突病变与更大的纹理异质性相关。
