Volumetric blood flow measurement with color Doppler ultrasonography: the importance of visual clues.

Volumetric flow rates were obtained in an in vivo canine pulsatile flow model using color Doppler ultrasonography (CDUS) and timed collection (TC) over a range which included laminar and turbulent flow. CDUS demonstrated increasing flow disturbance as flow rates increased, with effects on velocity profile, diameter measurements, and flow symmetry. Data comparing CDUS and TC showed marked differences in laminar flow (regression: slope = 1.02; r2 = 0.93; mean error, 11%) and nonlaminar flow (slope = 0.53; r2 = 0.78; mean error, 26%). Assigning the angle of insonation precisely was crucial to measurement accuracy. CDUS quantitates volumetric blood flow with a reasonable degree of accuracy under laminar flow conditions. Visual clues provided by CDUS can help avoid errors associated with deviations from laminar flow.