Segmented 3D GRE-EPI optimized for BOLD fMRI at 9.4T

A segmented 3D GRE EPI was adapted and optimized specifically for BOLD fMRI at a 9.4T MR system. While EPI is widely used in fMRI, especially at UHF its application becomes challenging for instance for long echo trains used at high spatial resolution. In this work, investigations on the stability of the system, tSNR, flexible sequence design, different temporal phase correction schemes, and efficient use of the limited SAR budget were performed. Finally, a protocol for BOLD fMRI of the motor cortex at 1.0mm nominal isotropic resolution (FOV=200x215x44mm³) with a volume TR of 3 seconds was set up.