Journal: Brain Structure & Function

Article Title: A comparative study of the superior longitudinal fasciculus subdivisions between neonates and young adults

doi: 10.1007/s00429-022-02565-z

Figure Lengend Snippet: Group differences in all NODDI and DTI parameters in various SLF branches between neonates and adults

Article Snippet: For NODDI model fitting, we calculated the main NODDI metrics (NDI, ODI) through the NODDI MATLAB Toolbox software ( https://www.nitrc.org/projects/noddi_toolbox ) using all four shells data (Zhang et al. ) (Supplementary Fig. 4).

Techniques:

Journal: Human Brain Mapping

Article Title: Along‐tract statistics of neurite orientation dispersion and density imaging diffusion metrics to enhance MR tractography quantitative analysis in healthy controls and in patients with brain tumors

doi: 10.1002/hbm.25291

Figure Lengend Snippet: Working pipeline. Representation of the steps necessary for the along‐tract extraction of quantitative diffusion metrics. (a) Computation of neurite orientation dispersion and density imaging (NODDI) maps: voxel fraction of Gaussian anisotropic diffusion (extracellular volume fraction: FECV), voxel fraction of non‐Gaussian anisotropic diffusion (intracellular: FICV), voxel fraction of isotropic Gaussian diffusion (FISO), and orientation dispersion index (ODI) maps. The NODDI compartment maps were combined into a single 4‐dimensional volume visualized as RGB image (red for FECV, green for FICV, and blue for FISO). (b) Computation of diffusion tensor imaging (DTI) maps at b ‐value 711 s/mm 2 : fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD). (c) Computation of high angular resolution diffusion imaging (HARDI) maps at b ‐value 3,000 s/mm 2 : FA, MD, AD, and RD. Color‐coded FA maps display fibers with craniocaudal direction in blue, fibers with anteroposterior direction in green, and fibers with mediolateral direction in red. (d) Tractography reconstructions based on a q‐ball residual bootstrap algorithm. Red = arcuate fascicle (AF), brown = frontal aslant tract (FAT), yellow = inferior fronto‐occipital fascicle (IFOF), orange = uncinate fascicle (UF), cyan = cingulum (CING), blue = corticospinal tract (CST), green = optic radiation (OR). (e) Fiber reparameterization computed by the MATLAB Along‐Tract Stats toolbox. Details of each tract are reported in Supplementary Figure . (f) Skeleton of tract obtained by averaging the spatial coordinates of all streamline vertices and collapsing them in a single point. (g) Example of diffusion metric plotted in line graph: FA along left AF

Article Snippet: Once preprocessing was completed, the Watson‐NODDI model was fitted to the two‐shell dMRI datasets (NODDI acquisition: 60 directions at b ‐value 3,000 s/mm 2 , 35 directions at b ‐value 711 s/mm 2 , 11 B0 volumes) using the MATLAB NODDI toolbox ( http://mig.cs.ucl.ac.uk/Tutorial.NODDImatlab ) to extract the following NODDI maps (Figure ): voxel fraction of Gaussian anisotropic diffusion (extracellular volume fraction [FECV]), voxel fraction of non‐Gaussian anisotropic diffusion (intracellular volume fraction [FICV]), voxel fraction of isotropic Gaussian diffusion (FISO), and orientation dispersion index (ODI) maps.

Techniques: Diffusion-based Assay, Imaging