Motivation: A common source of problems in MRI sequence development and optimization is the transfer of the sequence between simulation and measurement. By using a single sequence definition understood by both, this could be avoided. Goal(s): Enable the use of a single definition of an MRI sequence for simulation, optimization of sequence parameters, and measurement. Approach: PyPulseq is integrated with a fast, physics-based simulation, which allows a single sequence definition to be used for both simulation and measurement. Automatic differentiation allows efficient optimization of sequence parameters based on the simulated reconstruction. Results: Timing and variable flip angles of two PyPulseq examples were successfully optimized. Impact: Pulseq is a widely used and vendor agnostic library for writing MRI sequences. With pulseq-zero, existing and new sequence scripts can be simulated and optimized directly, with only minor modifications. The resulting sequences can be measured on real scanners immediately.
Endres et al. (Tue,) studied this question.