Efficient method to design RF pulses for parallel excitation MRI using gridding and conjugate gradient

[摘要] Parallel excitation (pTx) techniques with multiple transmit channels have been widely used in high field MRI imaging to shorten the RF pulse duration and/or reduce the specific absorption rate (SAR). However, the efficiency of pulse design still needs substantial improvement for practical real-time applications. In this paper, we present a detailed description of a fast pulse design method with Fourier domain gridding and a conjugate gradient method. Simulation results of the proposed method show that the proposed method can design pTx pulses at an efficiency 10 times higher than that of the conventional conjugate-gradient based method, without reducing the accuracy of the desirable excitation patterns.

[学科分类] 外科医学

[关键词] Radio frequency pulse design (RF pulse design);parallel excitation (pTx);high field magnetic resonance imaging (high field MRI);MRI coil array;gridding