A preparation sequencing system and methods are disclosed for generating curvilinear taglines of altered magnetization in an imaging plane of an NMR image. A preparation sequencing module is disclosed for generating a sinusoidal gradient signal simultaneously with a continuous a radio frequency (RF) signal, wherein the sinusoidal gradient signal is shaped to generate a rotating on-resonance excitation plane such that each point in the imaged target volume is on-resonance at least once in a period corresponding to one full rotation of the excitation plane. The on-resonance excitation plane is configured to simultaneously generate a plurality of curvilinear or circular taglines of altered magnetization in the imaging plane.
