Microstructure size-distribution estimations with smooth and sharp non-uniform oscillating gradient spin-echo modulations

MELISA LUCILA GIMENEZ; PABLO JIMÉNEZ; LEONARDO PEDRAZA; DIANA BETANCOURTH; ANALIA ZWICK; GONZALO A. ALVAREZ

Proceedings of the International Society for Magnetic Resonance in Medicine

Wiley

Año: 2021 vol. 29

Morphological changes related to neurological diseases occur at micrometer scales. Obtaining such information non-invasively opens new paradigms for clinical diagnosis. We use the Non-uniform Oscillating Gradient Spin-Echo sequence to estimate microstructure size-distributions with high sensitivity based on probing a signal ?decay-shift? rather than a signal decay-rate. The ?decay-shift? arises with sharp gradient modulations. As fast ramps are prohibitive in clinical diagnosis, we evaluate the method using sharp and smooth gradient modulations. We show using simulations and proof-of-principle experiments with phantoms that mimic axon-bundles, that optimal estimation of the underlying microstructure-size distribution is obtained either using sharp or smooth modulations.