VOLUMETRIC BLOOD-FLOW MEASUREMENT WITH COLOR DOPPLER ULTRASONOGRAPHY - THE IMPORTANCE OF VISUAL CLUES

Volumetric flow rates were obtained in an in vivo canine pulsatile flo w model using color Doppler ultrasonography (CDUS) and timed collectio n (TC) over a range which included laminar and turbulent flow. CDUS de monstrated increasing flow disturbance as flow rates increased, with e ffects 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 f low (slope = 0.53; r2 = 0.78; mean error, 26%). Assigning the angle of insonation precisely was crucial to measurement accuracy. CDUS quanti tates 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.