Abstract #3999

Brain Metabolites Diffuse "Freely" in White and Grey Matters: New Insights Into Cellular Architecture by Diffusion-Weighted Spectroscopy in the Human Brain.

Chlo Najac¹,², Francesca Branzoli³, Itamar Ronen⁴, Julien Valette¹,²

¹CEA-MIRCen, Fontenay-aux-Roses, France; ²CEA-CNRS URA 2210, Fontenay-aux-Roses, France; ³C. J. Gorter Center for High Field MRI, Leiden University Medical Center, Leiden, Netherlands; ⁴C. J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, Netherlands

Diffusion-weighted spectroscopy allows probing the intracellular environment. Here we investigate the diffusion of NAA, creatine and choline at long td (from 100 to 720 ms) in two voxels containing different proportions of white matter (WM) and grey matter (GM) in the Human brain. Metabolite apparent diffusion coefficient (ADC) barely depends on td, neither in predominantly WM, nor predominantly GM voxels. The stability of metabolites ADC with td suggests that, in both tissues, observed metabolite diffusion is essentially free, as would occur parallel to long fibers. This study offers a unique insight into WM and GM cellular architecture.