Design, modeling, construction and first experimental results of the ultra high performance H12 insertable head gradient set for 10.5T

Motivation: Increased gradient performance can address several technical and physics challenges of UHF MRI. Goal(s): To develop a head gradient coil (known as H12) optimized for both PNS and magnet interaction, for insertion into the body gradient coil of a 10.5T MRI system. Approach: H12 was designed to simultaneously minimize PNS and magnet heating while fitting inside the Siemens SC72 body gradient. Results: The hardware limits of H12 exceed Gmax 200mT/m and Smax 900T/m/s using 950A, 2000V gradient drivers. Thermal results demonstrate cooling capacity >35kW. PNS thresholds should be ~10-fold higher than body gradients and up to 3-fold higher than other head gradients. Impact: H12 gradient performance (Gmax*Smax) is considerably higher than other state-of-the-art gradient coils. When combined with 10.5T B0, we expect that H12 will provide major sensitivity and resolution increases for dMRI and fMRI. Experimental results to date are confirming these expectations.