Published in: Interface Focus. 2025 Apr 4;15(1):20240041. doi: 10.1098/rsfs.2024.0041.
Abstract
A phase-sensitive diffusion tensor magnetic resonance imaging (MRI) sequence is proposed with pulse timing optimization scheme to achieve velocity resolution of less than 20 μm s−1 and an integrated image reconstruction and velocity map generation pipeline. The application of ultra-slow flow relevant to neurofluids is enabled by the use of a recently developed, ultra-high-performance brain MRI gradient system. By simultaneously reconstructing magnitude and phase data, both metrics that characterize diffusive fluid motion and coherent velocity maps are calculated non-invasively in human subjects, time-resolved over the entire cardiac cycle. The resulting acquisition and reconstruction of velocity maps in brain parenchyma, enabled by high-performance brain imaging systems, promises to be an important approach to investigating ultra-slow neurofluid flow and glymphatic circulation.