Mitigation of near-band balanced steady-state free precession through-plane flow artifacts using partial dephasing.

Autor: Datta A; Stanford University, David Packard Electrical Engineering 350 Serra Mall, Rm. 308, Stanford, California, USA., Cheng JY; Stanford University, David Packard Electrical Engineering 350 Serra Mall, Rm. 308, Stanford, California, USA., Hargreaves BA; Stanford University, David Packard Electrical Engineering 350 Serra Mall, Rm. 308, Stanford, California, USA., Baron CA; Stanford University, David Packard Electrical Engineering 350 Serra Mall, Rm. 308, Stanford, California, USA., Nishimura DG; Stanford University, David Packard Electrical Engineering 350 Serra Mall, Rm. 308, Stanford, California, USA.
Jazyk: angličtina
Zdroj: Magnetic resonance in medicine [Magn Reson Med] 2018 Jun; Vol. 79 (6), pp. 2944-2953. Date of Electronic Publication: 2017 Oct 10.
DOI: 10.1002/mrm.26957
Abstrakt: Purpose: To mitigate artifacts from through-plane flow at the locations of steady-state stopbands in balanced steady-state free precession (SSFP) using partial dephasing.
Methods: A 60° range in the phase accrual during a TR was created over the voxel by slightly unbalancing the slice-select dephaser. The spectral profiles of SSFP with partial dephasing for various constant flow rates and during pulsatile flow were simulated to determine if partial dephasing decreases through-plane flow artifacts originating near SSFP dark bands while maintaining on-resonant signal. Simulations were then validated in a flow phantom. Lastly, phase-cycled SSFP cardiac cine images were acquired with and without partial dephasing in six subjects.
Results: Partial dephasing decreased the strength and non-linearity of the dependence of the signal at the stopbands on the through-plane flow rate. It thus mitigated hyper-enhancement from out-of-slice signal contributions and transient-related artifacts caused by variable flow both in the phantom and in vivo. In six volunteers, partial dephasing noticeably decreased artifacts in all of the phase-cycled cardiac cine datasets.
Conclusion: Partial dephasing can mitigate the flow artifacts seen at the stopbands in balanced SSFP while maintaining the sequence's desired signal. By mitigating hyper-enhancement and transient-related artifacts originating from the stopbands, partial dephasing facilitates robust multiple-acquisition phase-cycled SSFP in the heart. Magn Reson Med 79:2944-2953, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
(© 2017 International Society for Magnetic Resonance in Medicine.)
Databáze: MEDLINE
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