Daniel Posfai1, J. Andrew Derbyshire2, Daniel A. Herzka1
1Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, MD, United States; 2Tornado Medical Systems, Toronto, Ontario, Canada
Time-efficient gradient waveforms with pre-defined 1st moments (M1) can be difficult to design. These gradients are at the core of many techniques such as phase contrast or flow-compensated acquisitions. A new method of designing hardware-optimized gradient waveforms is presented. The design strategy works in both logical and physical coordinate systems, pushing gradient hardware to limitations. The method works directly on a rasterized time scale, and yields complete control of the 0th (M0), or M0 and M1 of waveforms. Design of an efficient balanced steady-state free precession (bSSFP) sequence is demonstrated, along with partially and fully M1-nulled (M1=0 mT/m*us2) variants useful for flow-compensated bSSFP.
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