Volume flow rate of common carotid artery measured by Doppler method and Color Velocity Imaging Quantification (CVI-Q).
BACKGROUND
Common carotid artery (CCA) volume flow rate (VFR) is clinically useful for study of cerebrovascular disease. Color Velocity Imaging Quantification (CVI-Q; Philips Ultrasound International, Irvine, CA), previously reported as accurate and reliable, tracks the flow lumen over the cardiac cycle, as well as mean spatial velocity, which is multiplied by vessel area to obtain VFR. VFR can also be obtained by Doppler sampling for mean velocity, and vessel area based on static B-mode lumen diameter. We compared CCA VFR by CVI-Q and Doppler method (DM), since knowledge of how they compare is crucial when both are used clinically.


METHODS
We prospectively studied patients having clinical carotid duplex exams and healthy controls. All had CCA VFR measured by both methods in the same exam session.


RESULTS
Thirty-four studies were reviewed. CCA VFR by CVI-Q in those without ICA stenosis was 337 +/- 96 mL/m, and by DM 359 +/- 130 mL/m; P = .33. There was no difference between methods for 50-75% or 75-95% ICA stenosis. In 7 patients with ICA occlusion, and 3 with 95-99% stenosis, VFR was higher by DM than by CVI-Q (Occlusion: 125 vs 58 mL/m, P = .007; 95-99%: 152 vs 63 mL/m, P = .038). There was no statistically significant difference between methods for measurement of the ratio of VFR between right and left CCA.


CONCLUSIONS
In patients with 0-95% ICA stenosis, VFR by CVI-Q and DM showed no difference. For 95-100% ICA stenosis the methods differ; with higher VFR by DM. Side-to-side VFR ratios remain constant, irrespective of VFR method, and can still provide clinically useful information.
Department of Neurology, Department of Medicine, Faculty of Medicine, Thammasat University, Patumthani, Thailand.
Pornpatr
P
Likittanasombut
Patrick
P
Reynolds
Dana
D
Meads
Charles
C
Tegeler
D001783:Blood Flow Velocity / Q000502:physiology; D017536:Carotid Artery, Common; D016893:Carotid Stenosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D016022:Case-Control Studies; D006801:Humans; D011446:Prospective Studies; D018615:Ultrasonography, Doppler, Color