Self-gated Fourier velocity encoding.
Self-gating is investigated to improve the velocity resolution of real-time Fourier velocity encoding measurements in the absence of a reliable electrocardiogram waveform (e.g., fetal magnetic resonance or severe arrhythmia). Real-time flow data are acquired using interleaved k-space trajectories which share a common path near the origin of k-space. These common data provide a rapid self-gating signal that can be used to combine the interleaved data. The combined interleaves cover a greater area of k-space than a single real-time acquisition, thereby providing higher velocity resolution for a given aliasing velocity and temporal resolution. For example, this approach provided velocity spectra with a temporal resolution of 19 ms and velocity resolution of 22 cm/s over an 818 cm/s field-of-view. The method was validated experimentally using a computer-controlled pulsatile flow apparatus and applied in vivo to measure aortic-valve flow in a healthy volunteer.
Macgowan
Christopher K
CK
Department of Medical Biophysics, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada. chris.macgowan@utoronto.ca
Liu
Garry K C
GK
van Amerom
Joshua F P
JF
Sussman
Marshall S
MS
Wright
Graham A
GA
D000465:Algorithms; D001021:Aortic Valve / Q000033:anatomy & histology* / Q000502:physiology*; D001783:Blood Flow Velocity / Q000502:physiology*; D005583:Fourier Analysis; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012212:Rheology / Q000379:methods*; D012680:Sensitivity and Specificity