Development of the H12 insertable head gradient set designed for 10.5T and optimized for both peripheral nerve stimulation and magnet heating

Motivation: Two interactions between gradient coils and their environment severely limit imaging performance: stimulation of peripheral nerves in human subjects and deposition of heat energy into the superconducting main magnet leading to helium loss or quench. This heating increases significantly for higher B0 and gradient switching frequencies. Goal(s): To address the above limitations by recasting the gradient design problem in a unique way to simultaneously minimize both of these interactions. Approach: Using these new methods, we designed and modeled a head gradient coil: H12. Results: We achieved >1.4 fold PNS improvement and >6 fold lower magnet heating compared to existing state-of-the-art head gradient coils. Impact: Our method allows the design and real-world use of stronger and faster-switching gradients than any in existence, while minimizing peripheral nerve stimulation and excessive magnet heating. The potential impact is especially high for head gradients operating at ultra high field.