Reproducibility of the Standard Model of diffusion in white matter on clinical MRI systems

• DOI: 10.1016/j.neuroimage.2022.119290
• Publication Date: 2022-05-08T21:35:15Z
• Authors: Santiago Coelho; Steven H. Baete; Gregory Lemberskiy; Benjamin Ades-Aron; Genevieve Barrol; Jelle Veraart; Dmitry S. Novikov; Els Fieremans
• Keywords: Repeatability

Estimating intra- and extra-axonal microstructure parameters, such as volume fractions diffusivities, has been one of the major efforts in brain imaging with MRI. The Standard Model (SM) diffusion white matter unified various modeling approaches based on impermeable narrow cylinders embedded locally anisotropic space. However, estimating SM parameters from a set conventional MRI (dMRI) measurements is ill-conditioned. Multidimensional dMRI helps resolve estimation degeneracies, but there remains need for clinically feasible acquisitions that yield robust parameter maps. Here we find optimal multidimensional protocols by minimizing mean-squared error machine learning-based estimates two 3T scanners corresponding gradient strengths 40and80mT/m. We assess intra-scanner inter-scanner repeatability 15-minute scanning 20 healthy volunteers twice both scanners. coefficients variation all except free water fraction are ≲10% voxelwise 1-4% their region-averaged values. As achieved reproducibility outcomes similar to those tensor imaging, our results enable vivo mapping neuroscience research clinic.