Diffusion magnetic resonance imaging offers unique in vivo sensitivity to tissue microstructure in brain white matter, which undergoes significant changes during development and is compromised in virtually every neurological disorder. Yet, the challenge is to develop biomarkers that are specific to micrometer-scale cellular features in a human MRI scan of a few minutes. Here we quantify the sensitivity and specificity of a multicompartment diffusion modeling framework to the density, orientation and integrity of axons. We demonstrate that using a machine learning based estimator, our biophysical model captures the morphological changes of axons in early development, acute ischemia and multiple sclerosis (total N=821). The methodology of microstructure mapping is widely applicable in clinical settings and in large imaging consortium data to study development, aging and pathology.
@article{arxiv.2307.16386,
title = {Mapping tissue microstructure of brain white matter in vivo in health and disease using diffusion MRI},
author = {Ying Liao and Santiago Coelho and Jenny Chen and Benjamin Ades-Aron and Michelle Pang and Ricardo Osorio and Timothy Shepherd and Yvonne W. Lui and Dmitry S. Novikov and Els Fieremans},
journal= {arXiv preprint arXiv:2307.16386},
year = {2024}
}