Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN 47405, USA; Program of Neuroscience, Indiana University, Bloomington, IN 47405, USA.
Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN 47405, USA; Program of Neuroscience, Indiana University, Bloomington, IN 47405, USA.
Magn Reson Imaging. 2020 Jun;69:1-7. doi: 10.1016/j.mri.2020.02.010. Epub 2020 Feb 20.
Segmentation of brain tissue in diffusion MRI image space has some unique advantages. A novel segmentation method using the direction-averaged diffusion weighted imaging (DWI) signal is proposed. Two images can be obtained from the fitting of the direction-averaged DWI signal as a function of b-value: one with superior contrast between the gray matter and white matter; one with prominent CSF contrast. A pseudo T1 weighted image can be constructed and standard segmentation tools can be applied. The method was tested on the HCP dataset using SPM12, and showed good agreement with segmentation using the T1 weighted image with the same resolution. The Dice score was all greater than 0.88 for GM or WM with full DWI data and very stable against subsampling of the DWI data in number of diffusion directions, number of shells, and spatial resolution.
在扩散 MRI 图像空间中进行脑组织分割具有一些独特的优势。提出了一种使用平均扩散加权成像（DWI）信号的新分割方法。可以从拟合方向平均 DWI 信号作为 b 值的函数中获得两个图像：一个图像具有灰质和白质之间的优异对比度；一个图像具有突出的 CSF 对比度。可以构建伪 T1 加权图像，并应用标准分割工具。该方法在 HCP 数据集上使用 SPM12 进行了测试，与使用相同分辨率的 T1 加权图像进行分割具有很好的一致性。对于具有完整 DWI 数据的 GM 或 WM，Dice 评分均大于 0.88，并且对 DWI 数据在扩散方向数量、壳数量和空间分辨率方面的采样非常稳定。
