title: VERSE-guided numerical RF pulse design: a fast method for peak RF power control.
abstract: In parallel excitation, the computational speed of numerical radiofrequency (RF) pulse design methods is critical when subject dependencies and system nonidealities need to be incorporated on-the-fly. One important concern with optimization-based methods is high peak RF power exceeding hardware or safety limits. Hence, online controllability of the peak RF power is essential. Variable-rate selective excitation pulse reshaping is ideally suited to this problem due to its simplicity and low computational cost. In this work, we first improve the fidelity of variable-rate selective excitation implementation for discrete-time waveforms through waveform oversampling such that variable-rate selective excitation can be robustly applied to numerically designed RF pulses. Then, a variable-rate selective excitation-guided numerical RF pulse design is suggested as an online RF pulse design framework, aiming to simultaneously control peak RF power and compensate for off-resonance.
authors.affiliation: Department of Electrical Engineering, Magnetic Resonance Systems Research Laboratory, Stanford University, Stanford, California, USA. daeho@mrsrl.stanford.edu
authors.forename: Daeho
authors.initials: D
authors.lastname: Lee
authors.forename: William A
authors.initials: WA
authors.lastname: Grissom
authors.forename: Michael
authors.initials: M
authors.lastname: Lustig
authors.forename: Adam B
authors.initials: AB
authors.lastname: Kerr
authors.forename: Pascal P
authors.initials: PP
authors.lastname: Stang
authors.forename: John M
authors.initials: JM
authors.lastname: Pauly
mesh_terms: D000465:Algorithms; D016477:Artifacts; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008962:Models, Theoretical; D019047:Phantoms, Imaging; D011846:Radio Waves; D012680:Sensitivity and Specificity; D012985:Software Design