CMIC Seminar: Computational tools for mapping brain pathways across the human lifespan

Speaker: Anastasia Yendiki, Harvard Medical School
UCL Contact: Dominique Drai (Visitors from outside UCL please email in advance).
Date/Time: 06 Jul 16, 13:00 - 14:00
Venue: Roberts 106

Abstract

Neuroanatomists describe white-matter fiber bundles based on the anatomical regions that the bundles go through or next to. In this talk I will describe methods for mapping white-matter pathways from diffusion MRI data that take a similar approach; that is, they define pathways based on their anatomical neighbors, rather than coordinates in a template space.

First, I will discuss a method for automated reconstruction of known white-matter pathways that combines global probabilistic tractography with prior information on the neighboring anatomical structures of the pathways. I will show our recent extensions of this method to handle longitudinal data, and to map pathways in the infant brain. I will present results suggesting that this approach is robust to differences between the training subjects and test subjects. I will also discuss our efforts to extend the idea of defining bundles based on their anatomical neighborhood to an exploratory approach that does not rely on prior information.

Finally, I will suggest a path towards augmenting our prior knowledge on brain connections by combining independent measurements of these connections from chemical tracing, optical imaging, and diffusion MRI.

These measurements, which can only be obtained ex vivo, can then be used to validate and improve in vivo reconstructions of white-matter bundles.

Anastasia Yendiki

Anastasia received a Ph.D. in Electrical Engineering: Systems from the University of Michigan at Ann Arbor, where she worked on statistical image reconstruction for nuclear imaging. Her thesis addressed the analytical optimization of reconstruction methods with respect to lesion detectability. Upon graduation she moved to the Martinos Center for Biomedical Imaging to learn about functional MRI but quickly got distracted by the colorful strands of diffusion tractography. She is currently an Assistant Physicist at Massachusetts General Hospital and Assistant Professor in Radiology at Harvard Medical School. She develops TRACULA (TRActs Constrained by UnderLying Anatomy), a tool for automated probabilistic tractography that is distributed publicly as part of the FreeSurfer package and has been used in studies of a wide range of disease populations.