Submillimeter in vivo human brain diffusion MRI at 500 mT/m with concurrent field monitoring

Motivation: High-fidelity, artifact-free diffusion MRI (dMRI) in high-performance gradient systems requires more advanced encoding and reconstruction approaches than those widely used. Goal(s): To achieve ghosting- and eddy current distortion-free in vivo submillimeter human brain dMRI with concurrent field monitoring. Approach: A 16-ch clip on field probe system was integrated onto custom-built 72ch to map high-order field perturbations during the acquisition. SENSE-based reconstruction was informed with the monitored phase evolution as expressed in a 3rd-order spherical harmonic model. Results: Concurrent field monitoring reconstruction reduces non-linear Nyquist ghosting and geometric distortions generated by high-order eddy currents from ultra-strong diffusion gradients. Impact: We expect concurrent field monitoring to become essential in achieving high-quality image reconstruction as the adoption of high-performance gradients systems grows and image acquisition strategies evolve with more sophisticated image encodings.