# Mitigating Gyral Bias in Cortical Tractography via Asymmetric Fiber Orientation Distributions

arXiv: https://arxiv.org/abs/1904.03328 · HTML: https://mlsanity.com/paper/1904.03328/

## Key facts

- Cited by 3 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 6 Apr 2019.

## Built on by (most cited first, 3 of 3)

- [Superficial White Matter Analysis: An Efficient Point-cloud-based Deep Learning Framework with Supervised Contrastive Learning for Consistent Tractography Parcellation across Populations and dMRI Acquisitions](https://mlsanity.com/paper/2207.08975/) (2022)
- [Reconstructing the somatotopic organization of the corticospinal tract remains a challenge for modern tractography methods](https://mlsanity.com/paper/2306.05623/) (2023)
- [Bundle-specific Tractogram Distribution Estimation Using Higher-order Streamline Differential Equation](https://mlsanity.com/paper/2307.02825/) (2023)

## Abstract (arXiv)

Diffusion tractography in brain connectomics often involves tracing axonal trajectories across gray-white matter boundaries in gyral blades of complex cortical convolutions. To date, gyral bias is observed in most tractography algorithms with streamlines predominantly terminating at gyral crowns instead of sulcal banks. This work demonstrates that asymmetric fiber orientation distribution functions (AFODFs), computed via a multi-tissue global estimation framework, can mitigate the effects of gyral bias, enabling fiber streamlines at gyral blades to make sharper turns into the cortical gray matter. We use ex-vivo data of an adult rhesus macaque and in-vivo data from the Human Connectome Project (HCP) to show that the fiber streamlines given by AFODFs bend more naturally into the cortex than the conventional symmetric FODFs in typical gyral blades. We demonstrate that AFODF tractography improves cortico-cortical connectivity and provides highly consistent outcomes between two different field strengths (3T and 7T).