Rapid mesoscale 3D whole-brain MRF in the Next-Generation 7T brain scanner: challenges and advantages

3D MRF with spiral projection trajectory was implemented on the 7T NexGen scanner to take advantage of its SNR benefit and state-of-the-art gradient system. To achieve high-fidelity and high-efficiency multi-parameter mapping at the mesoscale, novel techniques were developed to overcome several technical challenges in performing this acquisition, including spiral residual gradient compensation, trajectory measurement, water-only excitation RF pulse, B0 correction, B1+ correction and frequency response correction. The proposed technical developments enabled high-quality whole-brain T1, T2, and proton density mapping at 1-mm isotropic resolution in 1 minute, and 560mm isotropic resolution in 4-minutes scan time.