title: Experimental demonstration of diffusion signal enhancement in 2D DESIRE images.
abstract: In magnetic resonance microscopy based on conventional Fourier encoding techniques, molecular self-diffusion leads to a loss in signal to noise ratio while also limiting the spatial resolution. As opposed to standard diffusion-weighted sequences, the DESIRE (Diffusion Enhancement of SIgnal and REsolution) method gains signal through diffusion via a signal difference measurement, corresponding to the total number of spins saturated by a localized pulse applied for a given amount of time. The higher the diffusion coefficient at that location, the larger the number of spins effectively saturated and thus the higher the difference in signal. While the method has been previously demonstrated in 1D, the availability of higher magnetic fields and gradient strengths has recently brought its development within reach in 2D. Here we report the implementation of 2D DESIRE and the first experimental evaluation of enhancements in water and thin silicone oil. Enhancement levels obtained by saturating a 60 μm diameter region (effectively ~140 μm) and allowing diffusion lengths of 28 μm or 7 μm, respectively, are consistent with theoretical predictions. The typical enhancement values are 100% in water and 20% in silicone oil.
authors.affiliation: NeuroSpin, Commissariat à l'Energie Atomique et aux Energies Alternatives, 91191 Gif-sur-Yvette, France. ileana.jelescu@cea.fr
authors.forename: Ileana O
authors.initials: IO
authors.lastname: Jelescu
authors.forename: Nicolas
authors.initials: N
authors.lastname: Boulant
authors.forename: Denis
authors.initials: D
authors.lastname: Le Bihan
authors.forename: Luisa
authors.initials: L
authors.lastname: Ciobanu