[Center specific duplex Doppler threshold values in carotid artery stenosis]

Abstract

Purpose: The traditional categorizations of color Doppler ultrasonography (CDUS) used for grading internal carotid artery stenosis are not consistent with the multicenter controlled randomized studies of carotid artery endarterectomy. The purpose of this study was to determine duplex Doppler threshold values specific to our center for classification of critical internal carotid artery stenosis which is determined according to the results obtained from multi-center clinical studies.

Materials and methods: CDUS and digital subtraction angiography examinations were performed in 147 patients who were considered suitable for carotid endarterectomy. Using the values of peak systolic velocity (PSV), end diastolic velocity and peak systolic velocity ratio (PSV ICA/CCA), the optimum duplex Doppler threshold values were determined for internal artery carotid stenoses by ROC (receiver operating characteristics) analysis.

Results: The most accurate threshold levels for detection of ICA stenoses were found to be a PSV 133 cm/s for 50-99% stenosis, PSV ICA/CCA 2.6 for 60-99% stenosis and PSV ICA/CCA 3.6 for 70-99% stenosis. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy estimated using optimal duplex criteria for identification of ICA stenoses were 88%, 85% 78%, 91%, 86% for 50-69%, 94%, 87%, 71%, 98%, 89% for 60-99% stenosis, 92%, 92%, 65%, 99%, 92% for 70-99% stenosis, respectively.

Conclusion: The duplex criteria established in our center have high accuracy. Every center should establish its own duplex criteria for the diagnosis of carotid artery stenosis.