Positive-Contrast Imaging with Phase-Perturbed Differenced SSFP

R. Reeve Ingle¹, Dwight G. Nishimura¹

A novel positive-contrast imaging technique is presented and analyzed via Bloch simulation and SPIO phantom imaging. The Phase-Perturbed Differenced SSFP (PDSSFP) sequence is obtained by perturbing alternate RF phases of a bSSFP sequence, yielding an alternating steady-state profile with large signal deviations localized to specific off-resonant frequencies. If acquisitions during even and odd TRs are subtracted, the resulting spectral profile contains signal peaks at these critical frequencies with s in between. By aligning the s with water and fat resonances, robust background suppression can be obtained while achieving high peak contrast from off-resonant spins.