Meeting Banner
Abstract #4261

Target-Pattern-Informed Variable-Density Trajectory Design for Low-SAR Pulse Design in Parallel Transmission

Rainer Schneider1, 2, Matthias Gebhardt1, Jens Haueisen2, Josef Pfeuffer1

1Siemens Healthcare, MR Application Development, Erlangen, Germany; 2Institute of Biomedical Engineering and Informatics, Ilmenau University of Technology, Ilmenau, Germany

A lot of work has been done towards SAR-constrained optimization in pTX. However, in clinical use these methods can be too computationally intensive for highly parameterized spatially selective pulses. We propose a target-pattern-driven variable-density k-space trajectory (TD) metric, which inherently offers significant RF hardware efficiency and a beneficial impact on local and global SAR performance. To evaluate potential benefits of the TD approach, an elaborate simulation study for an 8ch 3T whole-body multi-channel TX array was conducted. The TD method was applied to a 3D-selective stack-of-spirals trajectory and compared to equal and fixed variable-density designs for varying TX acceleration factors.

Abstract PDF Presentation Video

Keywords

accelerated acceleration accelerations according accuracy achieved additional adds aliasing allocation allows anatomy applicable applied approaches arbitrary array assessed audience beneficial biomedical blurring channel clearly clinical combination combines computational computed constant control degraded demands density dependence depicted design designs determine development directly distribution driven efficiently energy equal error evaluating except excitation exciting exemplary explicitly fidelity firstly fixed function gets global grid hardware heart hence highly improvements informatics informed inherently intensity intensive introduce leave length library local locations magnetization majority maps match medicine metric metrics microwave national normalized note offers optimal optimization optimized optimizer parallel parameterized particularly pattern peak performance physicists power practice previous principle project proposed proves pulse pulses reasonable reduce reducing reduction regime resolution rounds sampling scenarios schemes segment segmented selective shaped simulation simulations since sophisticated space spatial spatially spectral spiral spirals stack stay steps stepwise studio substantial target technology tends towards trajectories trajectory transmission unique variable varying voltage window words