Abstract
Purpose Atherosclerotic arteries are challenging to evaluate quantitatively using spectral
Doppler ultrasound because of the turbulent flow conditions that occur in relation
to the atherosclerotic stenoses. Vector velocity ultrasound is angle independent and
provides flow information, which could potentially improve the diagnosis of arterial
stenoses. The purpose of the study is to distinguish significant stenoses in the superficial
femoral artery (> 50% diameter reduction) from non-significant stenoses based on velocity
ratios derived from the commercially available vector velocity ultrasound technique
Vector Flow Imaging (VFI).
Materials and Methods Velocity ratios (intrastenotic blood flow velocity divided by pre- or poststenotic
velocity) from a total of 16 atherosclerotic stenoses and plaques in the superficial
femoral artery of 11 patients were obtained using VFI. The stenosis degree, expressed
as percentage diameter reduction of the artery, was determined from digital subtraction
angiography and compared to the velocity ratios.
Results A velocity ratio of 2.5 was found to distinguish clinically relevant stenoses with>50%
diameter reduction from clinically non-relevant stenoses with<50% diameter reduction
and the difference was statistically significant.
Conclusion The study indicates that VFI is a potential future tool for the evaluation of arterial
stenoses.
Key words
angiography - velocity ratio - atherosclerosis - peripheral arterial disease - vector
velocity ultrasound