Imaging at 400 mT/m with next-generation gradient driver technology on a high-performance gradient platform.

Motivation: To push the technology envelope in advanced brain structural and functional imaging by increasing the performance of an investigational MAGNUS platform to ≥400 mT/m with a 3-MVA SiC gradient driver. Goal(s): To demonstrate the technical feasibility of improving gradient performance using advanced SiC semiconductor MOSFET gradient driver architecture, without any gradient coil redesign. Approach: Integrate the high efficiency head only MAGNUS gradient with next generation SiC advanced gradient driver topology and evaluate technical performance. Results: Demonstration of high command waveform fidelity, quality assurance phantom testing and in-vivo human scanning with diffusion MRI at high resolution (0.8-mm) and ultra-high b-values (30,000 s/mm2) with TE(s)<50ms. Impact: Cumulative gains from gradient coil design and gradient driver topology enable imaging of the mesoscale, with increased sensitivity in estimation of elusive contrasts such as slow-flow characterization of neuro-fluids, effective intra-axonal radii, and time-dependent diffusivities.