title: Arterial MR imaging phase-contrast flow measurement: improvements with varying velocity sensitivity during cardiac cycle.
abstract: To reduce noise in velocity images of magnetic resonance (MR) phase-contrast measurements, the authors implemented and evaluated a pulse sequence that enables automatic optimization of the velocity-encoding parameter V(enc) for individual heart phases in pulsatile flow on the basis of a rapid prescan. This sequence was prospectively evaluated by comparing velocity-to-noise ratios with those from a standard MR flow scan obtained in the carotid artery in eight volunteers. This sequence was shown to improve velocity-to-noise ratios by a factor of 2.0-6.0 in all but the systolic heart phase and was determined to be an effective technique for reducing noise in phase-contrast velocity measurements.
authors.affiliation: MR Center, Institute of Experimental Clinical Research, Aarhus University Hospital, Skejby Sygehus, Brendstrupgaardsvej, DK-8200 Aarhus N, Denmark. steffen@mr.au.dk
authors.forename: Steffen
authors.initials: S
authors.lastname: Ringgaard
authors.forename: Sten A
authors.initials: SA
authors.lastname: Oyre
authors.forename: Erik M
authors.initials: EM
authors.lastname: Pedersen
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity; D017536:Carotid Artery, Common / Q000033:anatomy & histology* / Q000502:physiology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009200:Myocardial Contraction; D011673:Pulsatile Flow