The Added Value of Using Diffusion Tensor Imaging (DTI) Based Tractography Models Along with Conventional Brain Sections to Teach the Complex White Matter Anatomy of the Brain

There are separate poster presentation times for odd and even posters.
Odd poster #s – first hour
Even poster #s – second hour

Abstract Body : Introduction
White matter anatomy is a significant part of neuroanatomy but is quite complex. The best method to demonstrate the complex directionality of white matter is white fibre dissection (Klingler’s method), which requires facilities for freezing at -15 to -20°C, meticulous dissection skills and takes weeks to curate models. The easiest and least expensive method to teach white matter is to take brain sections in conventional planes (axial, coronal and sagittal) using a brain knife. However, the complex architecture of white matter fibres is often difficult to demonstrate in the 2D planes of brain sections, as white matter appears more or less homogenous. Diffusion Tensor Imaging (a type of MRI sequence) with tractography is used for the visualization of regions of brain where anisotropic diffusion of water occurs indicating white matter bundles. There is no sufficient data on the effect of adding a session of using Tractography models in addition to using simple brain sections on student learning. This warrants further exploration and hence the proposed study.
Materials and methods
We are creating a series of tractography models and simple anatomical brain sections to use in teaching. These sections are made from the formalin fixed specimen in the Department of Anatomy, Government Medical College, Thiruvananthapuram. The tractography models are created using DSI Studio software version: Chen Sep 30,2022 from a young adult subject data from Human Connectome Project, that is publicly available. Students with no prior knowledge of the neuroanatomy will be allowed to examine brain sections at conventional planes and will also be shown tractography models (either to manipulate by their own at workstations or using teacher led demonstrations).
Results
The models were visualized in whole brain tractography using sectioning tool to make it comparable to the sections seen on gross anatomy. The white matter fascicle direction was visualized clearly when brain sections are compared with tractography models. For instance, the supero-inferiorly directed fibres – the Posterior Limb of Internal Capsule and the Tapetum was seen as darker (compared to surrounding white matter) in axial sections. The direction was confirmed in the “blue” fibres in the tractography image, emphasizing the value of using simple sections to understand direction of fibres. Subcomponents of a specific white matter fibre group (Corpus callosum) were separately painted using paint tool in the software (eg. Genu, body, splenium and tapetum). Based on available literature we propose that the students’ spatial understanding of the white matter anatomy will be superior when brain sections along with tractography are combined to teach.
Conclusion
While fibre dissection for teaching white matter anatomy is rarely performed, and is cumbersome and expensive. However, taking conventional brain sections is easily done at any neuroanatomical laboratory. Addition of a tractography exercise to the learning by brain sections, is hypothesized to complement each other and provide a cost effective and simple solution for teaching complex white matter anatomy.
Acknowledgement: Data were provided [in part] by the Human Connectome Project, WU-Minn Consortium (Principal Investigators: David Van Essen and Kamil Ugurbil; 1U54MH091657) funded by the 16 NIH Institutes and Centers that support the NIH Blueprint for Neuroscience Research; and by the McDonnell Center for Systems Neuroscience at Washington University.