A novel anatomically-constrained global tractography approach to monitor sharp turns in gyri

Abstract

Tractography from diffusion-weighted MRI (DWI) has revolutionized the brain connectivity investigation in vivo but still lack of anatomical tools to overcome controversial situations and to investigate the fibers reconstruction within gyri. In this work, we propose a non-generative global spin-glass tractography approach using anatomical priors to constrain the tracking process by integrating the pial surface knowledge to manage sharp turns of fibers approaching the cortical mantel according to its normal direction. The optimum configuration is obtained using a stochastic optimization of the global framework energy, resulting from a trade-off between a first term measuring the discrepancy between the spin glass directions and the underlying field of orientation distribution functions (ODF) or mean apparent propagators (MAP) estimated from the DWI data, and a second term related to the curvature of the generated fibers. The method was tested on a synthetic 90° crossing phantom and on a real brain postmortem sample.