Variable-density spiral 3D tailored RF pulses.
A variable-density spiral method is presented for reducing three-dimensional tailored radiofrequency pulse duration. Pulse length reductions of 21-32% are possible, with only a small error in the desired excitation profile. The method is demonstrated using simulations, phantom experiments, and T(2)*-weighted images of brain regions with susceptibility-induced intravoxel dephasing. Four 19.7-ms shots were needed to excite a 5-mm-thick slice with reduced susceptibility artifacts in the sinus region at 3T.
Stenger
V Andrew
VA
Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA. stengerva@msx.upmc.edu
Boada
Fernando E
FE
Noll
Douglas C
DC
D016477:Artifacts; D001921:Brain / Q000033:anatomy & histology*; D003198:Computer Simulation; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D019047:Phantoms, Imaging; D011846:Radio Waves