Magnetic resonance measurement and reconstruction of the diffusion propagator

TL;DR

This paper demonstrates how to experimentally determine the diffusion propagator using magnetic resonance techniques, implementing a new method on a benchtop MR scanner to transform diffusion data into the propagator.

Contribution

The study introduces a practical MR-based method for measuring the diffusion propagator, integrating it into existing imaging sequences and validating it with experimental data.

Findings

Successfully implemented the method on a benchtop MR scanner.

The apparent diffusion propagator converges to the true propagator with ideal pulse conditions.

Provides a new approach for diffusion measurement in MR imaging.

Abstract

We demonstrate the experimental determination of the diffusion propagator using magnetic resonance (MR) techniques. To this end, a recently introduced method was implemented on a benchtop MR scanner and incorporated into profiling and imaging sequences. Diffusion encoding was obtained by three gradient pulse pairs, each applied around a respective 180$^\circ$ radiofrequency pulse. The data involving two independent wavenumbers were transformed from the measurement domain to the spatial domain, yielding an apparent diffusion propagator. For free diffusion, this apparent propagator converges to the true one when two of the pulse pairs are replaced with pulses of infinitesimal duration.