Development of a 3D Interactive Model for Teaching Intercortical Connectivity of Cerebral White Matter Tracts
Authors: Bergden Jessica , Stabio Maureen Estevez 
Published: November 2023

White matter tracts connect areas of the brain, spinal cord and body much like a highway system. In the past, the only way to visualize these white matter tracts was through cadaveric dissection of deep brain structures. Unfortunately these dissections, although extremely valuable for students, are challenging and time‐consuming, which limits their incorporation into the modern medical curriculum. With the advent of new imaging technologies, such as diffusion tensor imaging (DTI), it is possible to visualize this intricate cerebral superhighway in a living human brain. Through a process called tractography, the directional information within DTI datasets can be used to create 3D maps of fiber systems, their Cartesian directionality, and their connectivity patterns. A thorough understanding of intercortical networks is vital to interpret anatomical disconnections that occur when lesions intersect white matter tracts as seen in patients with neuropathologies such as stroke, multiple sclerosis and vascular dementias. Tractography not only has revolutionized diagnostic imaging, it also has enormous potential in the medical neuroscience classroom to help students visualize cerebral white matter networks. The goal of this project was to create an interactive tractography model of curvilinear cerebral white matter tracts, such as the fornix, corpus callosum and uncinate fasciculus, for use in medical and graduate neuroanatomy education. First, a de‐identified 3T diffusion‐weighted imaging (the raw form of DTI) dataset of a living, healthy adult subject was obtained. 3D Slicer was used to estimate the position and direction of fiber tracts and to generate a preliminary tractography model based on fractional anisotropy values. Then, the preliminary model was imported into Maya where it was virtually dissected into multiple objects, representing specific tracts, which can be manipulated individually. The user can zoom and rotate the model and as well as scroll over to select individual tracts at a time. The model can also be exported into web‐compatible HTML5 versions for use in online educational modules that include overlays, labels, and diagrammatic elements. In summary, this model allows students to (1) visualize major association, commissural, and projection white matter tracts in 3D; (2) independently explore the relationships of each tract to one another and to its global position within the brain; and (3) recognize intercortical connectivity patterns which underlie clinical loss of function in patients. This project fills a gap in medical neuroanatomy education where students often struggle to learn 3D cerebral architecture and lack opportunities to appreciate the myriad subcortical fiber systems. We are currently developing a supplemental case‐studies curriculum to link the clinical effects of various white matter lesions with the tracts illustrated in the 3D model. We anticipate that these case‐based hypothetical lesion scenarios will engage the learner by directly correlating patient care with 3D neuroanatomy. Future direction for this work will be to evaluate the efficacy of tractography models in the classroom for teaching intercortical connectivity of cerebral white matter tracts.