Delayed-focus pulses for magnetic resonance imaging: an evolutionary approach.
An evolutionary algorithm has been used to design a family of shaped radiofrequency pulses giving uniform absorption-mode excitation across a predetermined frequency band. By allowing a free precession interval before signal acquisition, time is left for field gradients to be switched and for undesirable transients to decay.
Wu
X L
XL
Department of Chemistry, University of Cambridge, England.
Xu
P
P
Freeman
R
R
D055590:Electromagnetic Phenomena; D005583:Fourier Analysis; D007089:Image Enhancement / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008962:Models, Theoretical; D013997:Time Factors