Balanced phase-contrast steady-state free precession (PC-SSFP): A novel technique for velocity encoding by gradient inversion

Michael Markl*, M. T. Alley, N. J. Pelc

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

41 Scopus citations

Abstract

A technique for measuring velocity is presented that combines cine phase contrast (PC) MRI and balanced steady-state free precession (SSFP) imaging, and is thus termed PC-SSFP. Flow encoding was performed without the introduction of additional velocity encoding gradients in order to keep the repetition time (TR) as short as in typical SSFP imaging sequences. Sensitivity to through-plane velocities was instead established by inverting (i.e., negating) all gradients along the slice-select direction. Velocity sensitivity (VENC) could be adjusted by altering the first moments of the slice-select gradients. Disturbances of the SSFP steady state were avoided by acquiring different flow echoes in consecutively (i.e., sequentially) executed scans, each over several cardiac cycles, using separate steady-state preparation periods. A comparison of phantom measurements with those from established 2D-cine-PC MRI demonstrated excellent correlation between both modalities. In examinations of volunteers, PC-SSFP exhibited a higher intrinsic signal-to-noise ratio (SNR) and consequently low phase noise in measured velocities compared to conventional PC scans. An additional benefit of PC-SSFP is that it relies less on in-flow-dependent signal enhancement, and thus yields more uniform SNRs and better depictions of vessel geometry throughout the whole cardiac cycle in structures with slow and/or pulsatile flow.

Original languageEnglish (US)
Pages (from-to)945-952
Number of pages8
JournalMagnetic resonance in medicine
Volume49
Issue number5
DOIs
StatePublished - May 1 2003

Keywords

  • Balanced SSFP
  • Cine MRI
  • Flow quantification
  • Phase contrast MRI
  • Velocity mapping

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging

Fingerprint Dive into the research topics of 'Balanced phase-contrast steady-state free precession (PC-SSFP): A novel technique for velocity encoding by gradient inversion'. Together they form a unique fingerprint.

Cite this