Research

Removing a brain tumor is a difficult task for neurosurgeons without the appropriate tools. Brain tumor surgery involves a decision process during presurgical planning that may compromise the safety of patients due to the increased risk of developing permanent disabilities. This risk will always be present, as long as neurosurgeons perform approaches without visualizing the position of critical brain structures or knowing their relationship with the tumor.  

Visualization of white matter pathways can be achieved by the use of tractography, a technology that involves the combination of acquisition of brain images through diffusion MRI, which are later reconstructed using generalized q-sampling imaging to obtain voxel-sized information such as quantitative anisotropy that allows to map white matter pathways in the brain. The mapping of brain connections involved in critical functions (e.g. vision, language) from one region to another may be used by neurosurgeons to preserve these pathways and safely remove the tumor without producing unnecessary damage and preventing patients from developing permanent disabilities. 

We collaborate with Duke CIVM to build expert-vetted, tractography atlases of the brain connections using ultra-high-resolution diffusion MRI data. 

This was achieved by tractography to generate trajectories of representative white matter fascicles. The trajectories were clustered and labeled by a team of experienced neuroanatomists. 

This atlas of the structural connectome represents normative neuroanatomical organization of human brain white matter, complementary to traditional histologically-derived and voxel-based white matter atlases, allowing for better modeling and simulation of brain connectivity for future connectomic studies as well as clinical and educational applications. 

Download: 

Reference: 

• Yeh FC, Panesar S, Fernandes D, Meola A, Yoshino M, Fernandez-Miranda JC, Vettel JM, Verstynen T. Population-averaged atlas of the macroscale human structural connectome and its network topology. NeuroImage. 2018 Sep 1;178:57-68.

Correlational Tractography

Correlational tractography is a novel tractography modality invented in our lab. It is designed to explore a group of subjects and understand the correlation of brain connections with a study variable.

The technique adopts a “tracking-the-correlation” paradigm to map fiber pathways correlated with a study variable. The statistical significance of the findings can be further tested by connectometry, which leverages multiple regression, partial correlation, or non-parametric correlation to derive correlational tractography and study the circuit mechanism. 

Correlational tractography has been used by ~200 publications to understand the structure-function relation in both healthy subjects and patients.

Shape Analysis of White Matter Pathways

Tool and documentation: 

Reference: 

• Yeh FC, Badre D, Verstynen T. Connectometry: a statistical approach harnessing the analytical potential of the local connectome. NeuroImage. 2016 Jan 15;125:162-71.
• Hula WD, Panesar S, Gravier ML, Yeh FC, Dresang HC, Dickey MW, Fernandez-Miranda JC. Structural white matter connectometry of word production in aphasia: an observational study. Brain. 2020 Aug 1;143(8):2532-44.

Differential Tractography

Differential tractography is another novel tractography modality invented in our lab. It aims to explore individual brain connections to find neuronal change that leads to better clinical diagnosis or prognosis evaluation.

Differential tractography uses a “tracking-the-differences” paradigm to track pathways with neuronal change in a patient. It can be applied to either longitudinal studies or cross-sectional studies. The approach boosts the sensitivity and specificity of the imaging findings through the fiber tracking algorithms.

We are currently applying the techiqnue to ALS patients, with an aim to achieve accurate early diagnosis.

Tool and documentation: 

Reference: 

• Yeh FC, Badre D, Verstynen T. Connectometry: a statistical approach harnessing the analytical potential of the local connectome. NeuroImage. 2016 Jan 15;125:162-71.2019 Nov 15;202:116131.