Probabilistic Tractography for Topographically Organized Connectomes

Med Image Comput Comput Assist Interv. 2016 Oct;9900:201-209. doi: 10.1007/978-3-319-46720-7_24. Epub 2016 Oct 2.

Abstract

While tractography is widely used in brain imaging research, its quantitative validation is highly difficult. Many fiber systems, however, have well-known topographic organization which can even be quantitatively mapped such as the retinotopy of visual pathway. Motivated by this previously untapped anatomical knowledge, we develop a novel tractography method that preserves both topographic and geometric regularity of fiber systems. For topographic preservation, we propose a novel likelihood function that tests the match between parallel curves and fiber orientation distributions. For geometric regularity, we use Gaussian distributions of Frenet-Serret frames. Taken together, we develop a Bayesian framework for generating highly organized tracks that accurately follow neuroanatomy. Using multi-shell diffusion images of 56 subjects from Human Connectome Project, we compare our method with algorithms from MRtrix. By applying regression analysis between retinotopic eccentricity and tracks, we quantitatively demonstrate that our method achieves superior performance in preserving the retinotopic organization of optic radiation.

Keywords: Bayesian inference; probabilistic tractography; visual path-way.

MeSH terms

  • Algorithms*
  • Bayes Theorem
  • Connectome / methods
  • Connectome / statistics & numerical data*
  • Diffusion Tensor Imaging
  • Humans
  • Likelihood Functions
  • Normal Distribution
  • Regression Analysis
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Visual Pathways / anatomy & histology*