Abstract #2646

Sequential-Segment Multi-Shot Auto-Calibration for GRAPPA EPI: Maximizing Temporal SNR and Reducing Motion Sensitivity

Jonathan R. Polimeni¹, Himanshu Bhat², Thomas Benner³, Thorsten Feiweier⁴, Souheil J. Inati⁵, Thomas Witzel¹, Keith A. Heberlein⁶, Lawrence L. Wald¹,⁷

¹A.A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA, United States; ²Siemens Medical Solutions, Charlestown, MA, United States; ³Siemens AG, Healthcare Sector, Erlangen, Bavaria, Germany; ⁴Siemens AG, Erlangen, Bavaria, Germany; ⁵National Institute of Mental Health, Bethesda, MD, United States; ⁶Siemens Healthcare USA, Charlestown, MA, United States; ⁷Harvard-MIT Division of Health Sciences and Technology , MIT, Cambridge, MA, United States

Conventional auto-calibration data acquisition strategies for accelerated EPI seek to match the echo spacing of the image data, and therefore employ a segmented EPI acquisition. This approach is vulnerable to patient movement or respiration-induced dynamic B0 changes. Here we introduce a new auto-calibration method based on acquiring multi-shot, multi-slice auto-calibration data where the multiple segments in a given slice are acquired sequentially in time, shortening the time interval between segments. Our results show that the proposed method provides higher temporal SNR and reduced motion sensitivity that the conventional approach, while maintaining the echo spacing of the image acquisition.