Evaluation of 3-D colour Doppler ultrasound for the measurement of proximal isovelocity surface area.
Three-dimensional (3-D) colour Doppler ultrasound (US) enables flow rate estimation across a diseased valve without the need for a priori geometric assumptions. This study quantitatively evaluates the accuracy of 3-D colour Doppler US for measuring the flow rate (8. 3-75 mL/s) through a valve using the proximal flow convergence field. Flow rate measurements by this 3-D technique underestimate flow through finite circular orifices due to two major sources of error: 1. surface area slicing technique (18.3% +/- 3.8%) and 2. Doppler angle effect (41.0% +/- 1.5%). Combined total underestimation is 51% +/- 3.3%. To utilize 3-D US, the development of an improved proximal isovelocity surface area (PISA) measurement technique and a correction factor for the Doppler angle effect is required.
deGroot
C
C
John P. Robarts Research Institute, London, Ontario, Canada.
Drangova
M
M
Fenster
A
A
Zhu
S
S
Pflugfelder
P W
PW
Boughner
D R
DR
D001783:Blood Flow Velocity; D003198:Computer Simulation; D006351:Heart Valves / Q000000981:diagnostic imaging*; D006801:Humans; D021621:Imaging, Three-Dimensional; D019047:Phantoms, Imaging; D018615:Ultrasonography, Doppler, Color