3D-EPI SWI at 0.5T

Motivation: 3D-EPI has shown great potential for susceptibility weighted imaging (SWI) on high field MRI due to its high sampling efficiency. It may be feasible to achieve fast and superior quality for SWI at low-field strength. Goal(s): To optimize a 3D-EPI SWI sequence at 0.5T for reasonable resolution and good SNR, as well as suppression of Nyquist ghost. Approach: A multi-shot 3D-EPI sequence was used to acquire SWI data, with acquisition parameters tuned based on literature. Linear phase correction and dual-polarity GRAPPA were used to remove Nyquist ghost. Results: 3D-EPI demonstrated good sensitivity to susceptibility difference in brain tissue on 0.5T. Impact: 0.5T with 3D-EP-SWI offers greater access than higher field strength MRI, and may meet clinical needs for diagnosis of cerebral diseases like cerebral microbleeds.