This paper presents a non-invasive method for visualizing the three-dimensional (3D) structure of major white matter fasciculi in the human brain using diffusion tensor magnetic resonance imaging (DT-MRI) and tractography. The technique, called "virtual in vivo interactive dissection" (VIVID), allows for the interactive delineation and visualization of white matter tracts in vivo, providing a new dimension to anatomical descriptions of the living human brain. The study used DT-MRI to visualize ten major white matter fasciculi, including the superior longitudinal (arcuate) fasciculus, inferior longitudinal fasciculus, superior fronto-occipital (subcallosal) fasciculus, inferior fronto-occipital fasciculus, uncinate fasciculus, cingulum, anterior commissure, corpus callosum, internal capsule, and fornix. These fasciculi were isolated and displayed as 3D-rendered objects, and the virtual tract maps obtained were faithful to classical descriptions of white matter anatomy documented in postmortem studies. The technique involves using diffusion tensor MRI to estimate the self-diffusion tensor in each voxel of a MR image dataset, and then using this information to estimate and display the principal orientation of anisotropic structures in vivo. The study also describes the use of a two-regions of interest approach to separate specific fasciculi from others, allowing for accurate visualization of individual tracts. The results demonstrate that the virtual tract maps obtained using this approach are faithful to classical neuroanatomical descriptions, and that the technique is non-invasive and can be used in a clinical setting. The study highlights the potential of DT-MRI for studying the morphology of white matter fasciculi and suggests that further research is needed to validate the results and improve the accuracy of tractography.This paper presents a non-invasive method for visualizing the three-dimensional (3D) structure of major white matter fasciculi in the human brain using diffusion tensor magnetic resonance imaging (DT-MRI) and tractography. The technique, called "virtual in vivo interactive dissection" (VIVID), allows for the interactive delineation and visualization of white matter tracts in vivo, providing a new dimension to anatomical descriptions of the living human brain. The study used DT-MRI to visualize ten major white matter fasciculi, including the superior longitudinal (arcuate) fasciculus, inferior longitudinal fasciculus, superior fronto-occipital (subcallosal) fasciculus, inferior fronto-occipital fasciculus, uncinate fasciculus, cingulum, anterior commissure, corpus callosum, internal capsule, and fornix. These fasciculi were isolated and displayed as 3D-rendered objects, and the virtual tract maps obtained were faithful to classical descriptions of white matter anatomy documented in postmortem studies. The technique involves using diffusion tensor MRI to estimate the self-diffusion tensor in each voxel of a MR image dataset, and then using this information to estimate and display the principal orientation of anisotropic structures in vivo. The study also describes the use of a two-regions of interest approach to separate specific fasciculi from others, allowing for accurate visualization of individual tracts. The results demonstrate that the virtual tract maps obtained using this approach are faithful to classical neuroanatomical descriptions, and that the technique is non-invasive and can be used in a clinical setting. The study highlights the potential of DT-MRI for studying the morphology of white matter fasciculi and suggests that further research is needed to validate the results and improve the accuracy of tractography.