Selective filters of translational molecular diffusion dynamics in human brain microstructures

Abstract

Digital Poster at the Annual Meeting of the International Society for Magnetic Resonance in Medicine ISMRM-ISMRT(May 4-9, 2024, Singapore)Motivation: Our primary aim is to enhance non-invasive tissue-microstructure characterization as a diagnostic paradigm through advanced MRI methods.Goals: We explore microscopic tortuosity in human white matter using the Non-uniform Oscillating-Gradient Spin-Echo (NOGSE) contrast in a clinical 3T MRI scanner.Approach: The NOGSE contrast was obtained by subtracting distinct OGSE acquisitions, allowing the discrimination of signals from molecules within specific brain compartments.Results: We found restriction sizes consistent with human histological findings and evidence that the dominant signals originate from extra-axonal spaces, supporting microscopic tortuosity effects. This compartment-size-specific contrast opens a path for diagnosis based on quantitative imaging.Impact: We characterize microscopic tortuosity mechanisms in human brain white matter through the Non-uniform Oscillating-Gradient Spin-Echo contrast, which targets the signal of confined molecules in specific microscopic sizes. This novel contrast, demonstrated at 3T MRI, promises a quantitative tissue-microstructure paradigm for the medical diagnosis of diseases.