Velocity Profiles in Stenosed Tube Models Using Magnetic Resonance Imaging

Abstract

A time-of-flight MRI velocity measurement technique is evaluated against corresponding LDV measurements in a constriction tube model over a range of physiologic flow conditions. Results from this study show that MR displacement images can: 1) be obtained within both laminar and turbulent jets (maximum stenotic Re≅4,200), 2) measure mean jet velocities up to 172 cm/s, and, 3) detect low forward and reverse stenosis (0≤L/D≤2). Regions between the jet termination point and re-establishment of laminar flow (Re≥1500, ≥1000, and ≥110 downstream of 40, 60, and 80 percent stenosis, respectively) cannot presently be detected by this technique.