White Matter Alteration of the Cingulum in Parkinson Disease with and without Dementia: Evaluation by Diffusion Tensor Tract–Specific Analysis

Diffusion tensor tractography images of the right cingulate. Fiber tracts (CFTs) and voxelization along with diffusion tensor tractography of the posterior CFTs. A, Sagittal section of the color-coded map was used to determine coronal sections at the level of the splenium of the corpus callosum and the middle of the corpus callosum. B, The seed ROI, including the entirety of the CFTs (light blue area), was placed manually on a coronal section of the color maps at the level of the splenium of the corpus callosum. C, The target region of interest, including the entirety of the CFTs (purple area), was placed manually on a coronal section of the color maps at the level of the center of the corpus callosum in the sagittal plane. D, A tractographic image of the right posterior CFTs was generated from the seed ROI (light blue line) to the target ROI (purple line). E, In this study, the posterior CFTs were defined as the CFTs between the seed ROI and the target ROI. Voxelization was performed along the right posterior CFTs between the seed ROI and the target ROI (purple voxels), and FA values in coregistered voxels were calculated.