Ramin Javan MD, Presenter: Nothing to Disclose

Asim F. Choudhri MD, Abstract Co-Author: Nothing to Disclose

Arash Meshksar MD, Abstract Co-Author: Nothing to Disclose

Jeffrey Robert Petrella MD, Abstract Co-Author: Advisory Board, Janssen Alzheimer Immunotherapy Speakers Bureau, Quintiles

There are increasing applications of MR diffusion tensor fiber tracking, which allows for delineation of multiple interconnecting white matter fiber tracts in the brain. Proper interpretation of this information requires understanding the complex 3D relationships, beyond that required for conventional cross-sectional neuroimaging. With the recent surge in rapid prototyping technologies, new opportunities have emerged for discovering innovative applications through low-cost 3D printers, which use virtual 3D datasets to construct solid forms in a layer-by-layer technique. We propose that this technology may offer additional advantages in the visualization of white matter tracts, in settings such as neurosurgical planning, patient counseling and resident training.

The challenge in the case of tractography lies in the fact that the data format of fiber tracts is not ideally suited for surface reconstruction methods used in medical applications. Fiber tracts are derived from tensor data, represented as eigenvalues and eigenvectors. This results in splines, directional lines in 3D space describing a curve, as opposed to 3D meshes, that is, a collection of surface triangles created through reconstruction of data from voxel based cross-sectional imaging. Methods for converting splines into 3D meshes for 3D printing purposes were investigated.

Successful conversion was achieved by utilizing three of the investigated diffusion analysis software packages, each of which allow export of tractography splines into a different usable format, specifically, DXF (AutoCAD Drawing Exchange Format), STL (Standard Tessellation Language) and OBJ (Wavefront Object). Such formats are importable into advanced graphic design software such as Autodesk 3DStudio Max. Subsequently, multicolor 3D printing was performed through a commercial website using gypsum based material with cyanoacrylate finish. Sample printed tracts include the corpus callosum, the corticospinal tract, the optic pathway, and the hippocampal connections.

Physical 3D printed models of fiber tractography may add a new dimension to the increasing applications of diffusion tensor imaging in research, education and patient care.

Javan, R, Choudhri, A, Meshksar, A, Petrella, J, The Fourth Dimension in Diffusion Tensor Fiber Tractography: Color 3D Printing.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12020703.html