Three-directional Myocardial Phase-Contrast Tissue Velocity MR Imaging with Navigator- Echo Gating: In Vivo and in Vitro Study 1 Jana G. Delfino, PhD Kevin R. Johnson, PhD Robert L. Eisner, PhD Susan Eder, RT Angel R. Leon, MD John N. Oshinski, PhD The study protocol was HIPAA compliant and institutional review board approved. Informed consent was obtained from all participants. The purpose of the study was to prospectively validate the capability of navigator-echo– gated phase-contrast magnetic resonance (MR) imaging for measurement of myocardial velocities in a phantom and to prospectively use the phase-contrast MR sequence to measure three-directional velocity in the myocardium in vivo in volunteers and in patients scheduled for cardiac resynchronization therapy. An excellent correlation be- tween the measured velocity and the true phantom motion (R = 0.90 for longitudinal velocity, R = 0.93 for circumfer- ential velocity) was observed. Myocardial velocities were successfully measured in 17 healthy volunteers (11 male, six female; mean age, 27.5 years  6.5 [standard devia- tion]) and 28 patients with heart failure (18 male, 10 female; mean age, 63.9 years  15.0). Velocity values were significantly lower in the patients than in the volun- teers. The time to peak velocity in the lateral wall of the patients, as compared with that in the volunteers, was delayed. Phase-contrast MR imaging can be combined with navigator-echo gating to measure three-directional myocardial tissue velocities in vivo.  RSNA, 2008 Supplemental material: http://radiology.rsnajnls.org/cgi /content/full/2463062155/DC1 1 From the Department of Biomedical Engineering, Geor- gia Institute of Technology/Emory University, 101 Woo- druff Cir, Suite 2001, Atlanta, GA 30322 (J.G.D., K.R.J., J.N.O.); and Departments of Radiology (R.L.E., J.N.O.) and Medicine, Division of Cardiology (S.E., A.R.L.), Emory Uni- versity School of Medicine, Atlanta, Ga. Received Decem- ber 18, 2006; revision requested February 16, 2007; revi- sion received March 23; accepted April 25; final version accepted August 1. Supported by the Wallace H. Coulter Foundation. Address correspondence to J.G.D. (e-mail: jana.delfino@gatech.edu ).  RSNA, 2008 ORIGINAL RESEARCH  TECHNICAL DEVELOPMENTS Radiology: Volume 246: Number 3—March 2008 917 Note: This copy is for your personal non-commercial use only. To order presentation-ready copies for distribution to your colleagues or clients, contact us at www.rsna.org/rsnarights.