Online Filtering Tractography : Tracking with anatomical priors

INTRODUCTION: This abstract investigates how the mask affects streamline tractography. The discrete binary mask is an aggressive stopping criterion that can result in a large proportion of prematurely stopping streamlines [1]. Recently, Smith et. al [2]. proposed a method called Anatomically Constrained Tractography, which interpolates partial volume fraction maps based on the structural T1-weighted image and uses thresholds to determine when to include or to exclude the streamline. We propose a method called Online Filtering Tractography (OFT) which is an extension of the modular Sequential Monte Carlo Tractography [3]. OFT propagates simultaneously multiple streamlines using the full partial volume fraction maps to enforce the tracking in the white matter (WM) and stop in gray matter (GM). Streamlines propagating in cerebrospinal fluid (CSF) partial volume fraction map are iteratively repressed. Results of OFT using partial volume fraction maps overcome some limits of tracking with binary mask.