Contrast Enhancement using Slice Selective Composite Continuous Rotation Adiabatic Pulses
Bartha R, Sun Z
Robarts Research Institute, University of Western Ontario
Slice selective continuous-rotation adiabatic full passage (CRAFP) pulses, a group of AFP pulses with alternating frequency sweep direction, were used to increase the magnitude of nonlinear phase dispersion generated by a customized localization by adiabatic selective refocusing (LASER) sequence. Significantly enhanced contrast was observed in a phantom with two compartments containing different concentrations of nickel(II) doped deionized water in comparison to a conventional spin-echo diffusion weighted (SEDW) sequence and to LASER using non-continuous-rotation AFP (NCRAFP) pulses. The CRAFP pulses were found to be sensitive to magnetic susceptibility with potential applications for contrast enhancement in the presence of paramagnetic agents.