Carotid Stenosis Assessment with Vector Concentration before and after Stenting

Area of Science:

• Medical Imaging
• Cardiovascular Ultrasound
• Interventional Cardiology

Background:

• Digital subtraction angiography (DSA) is the gold standard for carotid artery stenosis assessment but is invasive and uses radiation.
• Duplex ultrasound (DUS) is non-invasive but angle-dependent, potentially affecting accuracy.
• Vector flow imaging (VFI) offers angle-independent flow assessment.

Purpose of the Study:

• To compare vector concentration (VC) from VFI with duplex ultrasound (DUS) velocity estimates (PSV, EDV) against DSA for carotid artery stenosis.
• To evaluate VFI's utility in assessing carotid artery stenosis and post-stent treatment.

Main Methods:

• Eleven patients with symptomatic carotid artery stenosis underwent DUS, VFI, and DSA before and after stenting.
• Vector concentration (VC) was calculated from VFI data.
• Peak-systolic velocity (PSV) and end-diastolic velocity (EDV) were measured using DUS.

Main Results:

• VC demonstrated a strong negative correlation with DSA-determined stenosis degree (r = -0.79, p < 0.001).
• DUS-derived PSV (r = 0.68, p = 0.002) and EDV (r = 0.51, p = 0.048) showed moderate correlations with DSA.
• VFI-based VC measurements were more consistent with DSA than DUS velocity parameters.

Conclusions:

• Vector flow imaging (VFI) with vector concentration (VC) is a promising, angle-independent ultrasound method for carotid artery stenosis assessment.
• VC may be valuable for evaluating carotid artery stenosis severity and monitoring stent patency.