# Uncovering the time dependent diffusion coefficient in neural tissue with MRI

> **NIH NIH R01** · VANDERBILT UNIVERSITY MEDICAL CENTER · 2024 · $308,594

## Abstract

The overarching goal of this project is to reveal the microstructural features that underlie the
diffusion-time dependent changes in the apparent diffusion coefficient measured diffusion
weighted magnetic resonance imaging (DWI) in neural tissue. While time dependent changes in
the diffusion coefficient have been measured in numerous previous studies of neural tissue, the
exact microstructural characteristics of that underly these changes remain unclear. Uncovering
the microstructure that underly these measurements could improve the diagnosis, staging and
differentiation of numerous neurological diseases that otherwise show nonspecific changes with
DWI. We propose that time dependent changes in diffusion originate primarily from three
sources: mean axon diameter, heterogeneity of extra-axonal space, and orientation dispersion.
Within this project, we propose to (1) develop and use numerical simulations to test the
sensitivity of time dependent diffusion to tissue microstructure, (2) validate time dependent
changes in the diffusion coefficient in specific animal models that vary axon diameter,
heterogeneity of extra-axonal space, and complexity of white matter, and (3) provide baseline
estimates of the time dependent diffusion coefficient and the variability in these measurements
in a population of healthy human controls.

## Key facts

- **NIH application ID:** 10892115
- **Project number:** 5R01EB031954-04
- **Recipient organization:** VANDERBILT UNIVERSITY MEDICAL CENTER
- **Principal Investigator:** Kevin D Harkins
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $308,594
- **Award type:** 5
- **Project period:** 2021-09-24 → 2027-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10892115

## Citation

> US National Institutes of Health, RePORTER application 10892115, Uncovering the time dependent diffusion coefficient in neural tissue with MRI (5R01EB031954-04). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10892115. Licensed CC0.

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