Approximate solutions of the bloch equations for selective excitation

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)22_Publication in policy or professional journal

10 Scopus Citations
View graph of relations

Author(s)

Detail(s)

Original languageEnglish
Pages (from-to)83-95
Journal / PublicationJournal of Magnetic Resonance (1969)
Volume75
Issue number1
Publication statusPublished - 15 Oct 1987
Externally publishedYes

Abstract

Approximate solutions to the Bloch equations for selective excitation are derived using a perturbation method. High-order terms are analyzed, employing some special properties of corresponding multidimensional integrals. It is found that for excitation by a symmetric RF pulse applied in the presence of a field gradient the spin nutation angle as a function of the off-resonance frequency is approximately proportional to the Fourier dine transform of the RF function. This result is more accurate than the common assumption that the transverse magnetization as a function of the off resonance frequency is approximately proportional to the Fourier transform of the RF function. This analysis is useful for understanding the behaviors of both spin-inversion and phase-reversal 180° selective RF pulses as well as selective-excitation pulses, and it also offers insight to the problems of designing better selective RF pulses. © 1987.