Fig. 2
Pipelines for data processing. A Effective connectivity. â‘ Extraction of the time series of all brain regions in the Papez circuit. LACC, left anterior cingulate cortex; LATN, left anterior thalamic nuclei; LERC, left entorhinal cortex; LHPC, left hippocampus; LMB, left mamillary body; LPCC, left posterior cingulate cortex; LPHG, left parahippocampal gyrus; LSub, left subiculum; RACC, right anterior cingulate cortex; RATN, right anterior thalamic nuclei; RERC, right entorhinal cortex; RHPC, right hippocampus; RMB, right mamillary body; RPCC, right posterior cingulate cortex; RPHG, right parahippocampal gyrus; RSub, right subiculum. B ALPS. â‘ The dwi2tensor and tensor2metric are used to calculate the tensor metrics of fractional anisotropy (FA) and the diffusivity along the x-axis (right-left; Dxx), y-axis (anterior-posterior; Dyy), and z-axis (inferior-superior; Dzz); â‘¡ Register the FA image to the standard space (JHU-ICBM-FA template) and apply the deformation matrix to all diffusivity maps (Dxx, Dyy, Dzz); â‘¢ Place 5 mm diameter spheres on the projection fibers (superior corona radiata (SCR)) and association fibers (superior longitudinal fasciculus (SLF)) at the level of the left and right lateral ventricles; and â‘£ Obtain the X, Y, and Z directional diffusivity of these fibers. ALPS, along the perivascular space; FA, fractional anisotropy; Dxx, diffusivity along the x-axis (right-left); Dyy, diffusivity along the y-axis (anterior-posterior); Dzz, diffusivity along the z-axis (inferior-superior); JHU-ICBM, Johns Hopkins University - International Consortium for Brain Mapping; WM, white matter. C PVS volume. â‘ T1-weighted images were preprocessed; â‘¡ The PVS volume was extracted for quantitative analysis. PVS, perivascular space