Faculty of Health Science, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.
School of Allied Health Sciences, Kitasato University, Japan.
J Clin Neurosci. 2020 Apr;74:69-75. doi: 10.1016/j.jocn.2020.01.059. Epub 2020 Jan 29.
The aim of this study was to evaluate changes in measured volumes using Statistical Parametric Mapping (SPM) 12 caused by contrast changes in magnetic resonance (MR) image. Twenty-one healthy subjects participated in the study. From all subjects, 3D T1-weighted images (T1WIs) were obtained using a 3T scanner. In the first step of creating reference volume data, we used SPM12 to binarize all the segmented data. In the second step, we assigned simulated 3D-T1WI signal intensities to each tissue image and used the following values. The last step was integration of each tissue image to generate 3D-T1WI simulated reference volume data for each participant. To create the reference 3D-T1WIs with various contrasts from the reference volume data, we varied the signal intensity of gray matter from 900 to 600, 700, 1100, 1300, and 1400. The reference 3D-T2WI was acquired using the method used for 3D-T1WIs. Then, six 3D-T1WIs were processed using intrasubject bias-correction processing with SPM12, resulting in six new 3D-T1WIs of nonuniform signal intensities. Thirteen volume data sets were segmented into native-space tissue probability data using SPM12. Examination of the 3D data without nonuniform signal intensity showed that significant differences in measured volumes were not observed on repeated analysis of variance, but examination of the 3D data with nonuniform signal intensity did show significant differences in measured volumes in gray matter and CSF but not in white matter. Measured volumes using segmented tissue probability data obtained using SPM12 were not influenced by the contrasts of analyzed images.
本研究旨在评估磁共振（MR）图像对比变化引起的统计参数映射（SPM）12 测量体积的变化。21 名健康受试者参与了这项研究。所有受试者均采用 3T 扫描仪获得 3D T1 加权图像（T1WI）。在创建参考体积数据的第一步中，我们使用 SPM12 将所有分割数据二值化。在第二步中，我们为每个组织图像分配模拟的 3D-T1WI 信号强度，并使用以下值。最后一步是将每个组织图像整合起来，为每个参与者生成 3D-T1WI 模拟参考体积数据。为了从参考体积数据中创建具有不同对比度的参考 3D-T1WI，我们将灰质的信号强度从 900 到 600、700、1100、1300 和 1400 进行了变化。参考 3D-T2WI 是使用与 3D-T1WI 相同的方法获得的。然后，使用 SPM12 对 6 个 3D-T1WI 进行了个体间偏置校正处理，得到了 6 个新的非均匀信号强度的 3D-T1WI。使用 SPM12 将 13 个体积数据集分割为原始空间组织概率数据。在没有非均匀信号强度的情况下对 3D 数据进行检查表明，在重复方差分析中未观察到测量体积的显著差异，但对具有非均匀信号强度的 3D 数据进行检查时，发现灰质和 CSF 的测量体积存在显著差异，但在白质中则没有。使用 SPM12 获得的分割组织概率数据测量的体积不受分析图像对比度的影响。
