Measurement of carotid bifurcation pressure gradients using the Bernoulli principle

High diastolic flow velocities in severe internal carotid artery stenosis: A sign of increased surgical risk?

“…Instead, V d has been used to distinguish between lower and higher grade of ICA stenosis. 5,[18][19][20] However, Schwartz et al 21 suggested that the peak systolic flow velocity is the best single Doppler scanning parameter for distinguishing severe from lower grades of carotid stenoses.…”

Pressure Difference Estimation in Non-stenotic Carotid Bifurcation Phantoms Using Vector Flow Imaging

“…Firstly, the prestenotic velocity is assumed to be negligible compared with the distal velocity and is omitted from the calculation (Yoganathan et al 1988). This situation may occur in stenotic vascular diseases, but one study reported poor correlation between the systolic measured using the Doppler method and direct ∆𝑃 catheterization in patients with carotid stenosis (Illig et al 1996). Velocities acquired with spectral Doppler ultrasound are susceptible to being incorrect due to erroneous assumptions of the peak velocity direction (Hatle et al 1980;Lui et al 2005).…”

Non-Invasive Assessment of Intravascular Pressure Gradients: A Review of Current and Proposed Novel Methods

“…Invasive angiography is only indicated, when non-invasive methods are inconclusive, or when revascularization is clinically indicated. Correlations were reported to be weak to moderate for the carotid arteries, when Illig et al compared invasively measured pressure gradients with estimated pressure gradients derived from Doppler US using the simplified ( n = 77, r = 0.419, p < 0.0001) (Equation (1)) and the expanded Bernoulli equation ( n = 77, r = 0.374, p = 0.0008) (Equation (2)) [86]. Doppler US studies of the iliac arteries have reported results to be diverse with correlations ranging from weak to strong.…”