A global approach to cardiac tractography

Cardiac myofibrilles bundles in the human heart can be located by iteratively tracing the local water diffusion direction inferred from diffusion weighted MRI images. This well known process, called streamlining, needs to be initialized by a seed. In this paper, a global, graph modeling approach for cardiac myofibrille tractography is presented. Seed points are no longer needed : it predicts the fibers in one shot for the whole DT-MRI volume without initialization artifacts. The main merits of the presented methodology are its ability to give a unique estimation of the heart architecture (independent of seed initialization), the fact that it has no hyper- parameters and that it provides an optimal balance between the density of fibers and the amount of available data.

1. INTRODUCTION

In cardiac tractography, myofibrille paths are estimated by tracing iteratively the direction of maximal water diffusion estimated from diffusion weighted MRI images. Despite the potentially multi-directional environment within a voxel, water diffusion is highly anisotropic in most regions of the cardiac muscle and thus the direction of maximal water diffusion aligns with the myofibrille bundle direction. Such estimated fiber paths can be used to investigate and better understand the fiber architecture of the human heart and its muscular organization.