Neurodevelopmental Disorders Prevention Center, Perinatal Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States.
Imaging Research Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States; Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States.
Neuroimage. 2022 Dec 1;264:119727. doi: 10.1016/j.neuroimage.2022.119727. Epub 2022 Nov 1.
Preterm brains commonly exhibit elevated signal intensity in the white matter on T2-weighted MRI at term-equivalent age. This signal, known as diffuse excessive high signal intensity (DEHSI) or diffuse white matter abnormality (DWMA) when quantitatively assessed, is associated with abnormal microstructure on diffusion tensor imaging. However, postmortem data are largely lacking and difficult to obtain, and the pathological significance of DEHSI remains in question. In a cohort of 202 infants born preterm at ≤32 weeks gestational age, we leveraged two newer diffusion MRI models - Constrained Spherical Deconvolution (CSD) and neurite orientation dispersion and density index (NODDI) - to better characterize the macro and microstructural properties of DWMA and inform the ongoing debate around the clinical significance of DWMA. With increasing DWMA volume, fiber density broadly decreased throughout the white matter and fiber cross-section decreased in the major sensorimotor tracts. Neurite orientation dispersion decreased in the centrum semiovale, corona radiata, and temporal lobe. These findings provide insight into DWMA's biological underpinnings and demonstrate that it is a serious pathology.
早产儿的大脑在足月相等年龄的 T2 加权 MRI 上通常表现出白质信号强度升高。这种信号在定量评估时称为弥漫性过度高信号强度（DEHSI）或弥漫性白质异常（DWMA），与扩散张量成像上的异常微观结构有关。然而，尸检数据在很大程度上缺乏且难以获得，并且 DEHSI 的病理意义仍存在争议。在一个由 202 名在≤32 孕周出生的早产儿组成的队列中，我们利用了两种新的扩散 MRI 模型——约束球分解（CSD）和神经丝取向分散和密度指数（NODDI）——来更好地描述 DWMA 的宏观和微观结构特性，并为围绕 DWMA 的临床意义的持续争论提供信息。随着 DWMA 体积的增加，白质中的纤维密度普遍降低，主要感觉运动束中的纤维横截面积减小。在半卵圆中心、放射冠和颞叶，神经丝取向分散度降低。这些发现深入了解了 DWMA 的生物学基础，并表明它是一种严重的病理学。
