B0-Robustness and Exchange Weighting of Optimal Control Pulses Compared to State of the Art Pulses for CEST Imaging

Description

Saturation pulses are an essential part of CEST-MRI measurements and are responsible for the quality of Z-spectra. Different kinds of saturation pulses have been developed during the past fulfilling different criteria and practical applicability. In a recent work using optimal control (OC), it was possible to design pulses that perform almost identical to the theoretical optimal continuous-wave saturation. For all saturation strategies the exchange weighting and robustness to B0-inhomogeneities are essential properties. Therefore, these properties are analyzed for real-valued OC-pulses, and compared to classical Gaussian (G) and block pulse train (BPT) pulses, as well as recently developed saturation pulse strategies based on adiabatic Spin Lock (SL) pulses. We have found that the optimized pulse train generates superior CEST contrast and has high stability against B0-inhomogenities while maintaining the natural shape at the water peak which improves CEST-spectrum fitting and B0-correction.

Period	26 Jan 2023
Held at	University of Erlangen-Nürnberg, Germany
Degree of Recognition	Regional