Can echocardiographic particle image velocimetry correctly detect motion patterns as they occur in blood inside heart chambers? A validation study using moving phantoms.
OBJECTIVE
To validate Echo Particle Image Velocimetry (PIV) METHODS: High fidelity string and rotating phantoms moving with different speed patterns were imaged with different high-end ultrasound systems at varying insonation angles and frame rates. Images were analyzed for velocity and direction and for complex motion patterns of blood flow with dedicated software. Post-processing was done with MATLAB-based tools (Dflow, JUV, University Leuven).


RESULTS
Velocity estimation was accurate up to a velocity of 42 cm/s (r = 0.99, p < 0.001, mean difference 0.4 ± 2 cm/s). Maximally detectable velocity, however, was strongly dependent on frame rate and insonation angle and reached 42 cm/s under optimal conditions. At higher velocities estimates became random. Direction estimates did depend less on velocity and were accurate in 80-90%. In-plane motion patterns were correctly identified with three ultrasound systems.


CONCLUSIONS
Echo-PIV appears feasible. Velocity estimates are accurate, but the maximal detectable velocity depends strongly on acquisition parameters. Direction estimation works sufficiently, even at higher velocities. Echo-PIV appears to be a promising technical approach to investigate flow patterns by echocardiography.
Dept, of Cardiovascular Diseases, University Hospital Gasthuisberg, Catholic University Leuven, Herestraat 49, 3000 Leuven, Belgium.
Christian
C
Prinz
Reka
R
Faludi
Andrew
A
Walker
Mihaela
M
Amzulescu
Hang
H
Gao
Tokuhisa
T
Uejima
Alan G
AG
Fraser
Jens-Uwe
JU
Voigt
D001783:Blood Flow Velocity / Q000502:physiology*; D018618:Echocardiography, Doppler, Color / Q000379:methods*; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D007089:Image Enhancement; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012212:Rheology / Q000379:methods*; D016276:Ventricular Function / Q000502:physiology*