An improved algorithm for design of broadband excitation, inversion, and mixing pulse sequences by iterative optimization of phases: TOPS-2

被引：0

作者：

Jacob, Justin ^{[1
]}

Shetty, Tejas ^{[2
]}

Khaneja, Navin ^{[1
]}

机构：

[1] Indian Inst Technol, Syst & Control Engn Dept, Powai 400076, India

[2] Indian Inst Technol, Dept Phys, Powai 400076, India

来源：

JOURNAL OF MAGNETIC RESONANCE | 2023年 / 353卷

关键词：

Bloch equation; Broadband excitation; Broadband inversion; Chemical shift; Composite pulse; Phase modulation; Scalar triple product; 2-D NMR; COMPOSITE PULSES; POPULATION-INVERSION; NMR;

D O I：

10.1016/j.jmr.2023.107501

中图分类号：

Q5 [生物化学];

学科分类号：

071010 ; 081704 ;

摘要：

This paper presents an improved iterative algorithm (TOPS-2) for the design of broadband inversion, excitation and coherent transfer mixing sequence (TOCSY) pulses. The evolution of the Bloch vector is presented as a sequence of small constant flip angle pulses with varying phases and constant amplitude. This paper describes an improved algorithm for iterative optimization of piece-wise constant phases as we incorporate the quadratic terms in the propagators. In our iterative optimization we obtain a closed-form expression for each phase, and these phases are optimized sequentially using the new improved algorithm. This paper compares the simulation results of the TOPS vs TOPS-2 and shows that TOPS-2 perform better. Experimental validation of excitation and inversion TOPS-2 pulse sequence is performed with .5% H2O in 99.5% D2O, and experimental validation of TOPS-2 mixing (TOCSY) pulse sequence is done with 0.1% of Ethylbenzene (EB) in CDCl3 solvent.& COPY; 2023 Elsevier Inc. All rights reserved.

引用

页数：6