Fig. 1. Benefits of strong gradients for diffusion MRI.

High gradient amplitudes up to 300 mT/m on the Connectome system (bottom) achieve a given diffusion-encoding gradient area in less time compared to conventional gradient systems (top), as illustrated through the pulsed gradient spin echo diffusion MRI sequence. Benefits of strong diffusion-encoding gradients include shortening the entire diffusion-encoding period and echo time (TE), and hence increasing the signal-to-noise ratio (SNR) by reducing signal loss due to T2 decay. The larger gradient amplitudes also enable stronger diffusion encoding (i.e., larger diffusion-encoding gradient areas, larger q- values and b-values) to be achieved with shorter diffusion times, providing higher “diffusion resolution” to improve the capability of resolving smaller length-scales for probing tissue microstructure and for resolving complex white matter structures such as crossing fibers. RF = radiofrequency, δ = diffusion-encoding gradient pulse duration, Δ = diffusion time.