Validation of volume flow measurements in blood vessels with quantitative color velocity imaging using a physiologic model of the circulation.
OBJECTIVE
Color velocity imaging-quantitative (CVI-Q) is a new sonographic technique designed to measure volume flow (VF) in blood vessels. We attempted to validate VF measurements with CVI-Q in an in vitro model of the circulation.


METHODS
We validated CVI-Q in a flow phantom mimicking physiologic conditions by connecting isolated porcine arteries 4-14 mm in diameter to a calibrated perfusion roller pump generating pulsatile flow with porcine blood. Pump flow was varied stepwise from 0 to 1,000 ml/min. CVI-Q VF measurements were performed using a 7.5-MHz linear array transducer. VF results then were compared with pump flow calibration values through linear regression.


RESULTS
A good correlation (r2 = .98-.99, slope = 0.88-1.02) was obtained from 0 to 400-600 ml/min. The degree of correlation depended on vessel diameter, with linearity being maintained over a somewhat larger range in medium-sized vessels. At higher flows, variability increased significantly.


CONCLUSIONS
VF measurements with CVI-Q are accurate in a physiologic flow range. At supraphysiologic flow rates, as are encountered within arteriovenous fistulae, CVI-Q may give inaccurate results. Awareness of possible pitfalls and limitations of the technique is important for obtaining accurate and reproducible results.
Levy
D J
DJ
Department of Pediatrics, UCLA School of Medicine, USA.
Westra
S J
SJ
Sayre
J
J
Kimme-Smith
C
C
D000818:Animals; D001158:Arteries / Q000502:physiology; D001783:Blood Flow Velocity; D006801:Humans; D066298:In Vitro Techniques; D015203:Reproducibility of Results; D013552:Swine; D018615:Ultrasonography, Doppler, Color / Q000379:methods*