Optimizing the gVERSE RF Pulse Design via Optimal Control

Magnetic Resonance Imaging (MRI) is an advanced tomographic technique that is able to produce high resolution cross-sectional images of an object or specimen by exploiting Radio Frequency (RF) pulses. A Variable Rate Selective Exci-tation (VERSE) pulse is a type of RF pulse that reduces the Specific Absorption Rate (SAR) of molecules in a specimen; SAR leads to an increase in patient temperature during MRI procedures. We develop a selective VERSE pulse that is designed to minimize SAR while preserving its duration and slice profile, called the generalized VERSE (gVERSE), because it allows more general variations of the slice gradient waveform. After the formulation of a rigorous mathematical model that is aimed at minimizing SAR RF levels, the nonlinear gVERSE problem is subsequently solved as an optimal control problem. Using state of the art Sparse Optimal Control Software (SOCS)