Anthony Carnicelli, Jonathan Stone, Adam J. Doyle, David Gillespie, Michael Singh, Jason Kim, Baback Jahromi, Ankur Chandra
University of Rochester Medical Center, Rochester, NY.
OBJECTIVES: Previous studies have shown poor correlation of duplex velocity criteria and contrast angiography for quantifying carotid stenosis in the setting of contralateral carotid artery occlusion. CT angiography (CTA) is frequently used for evaluation of carotid stenosis. This study aimed to determine whether CTA-derived cross-sectional area correlates to duplex velocity criteria for carotid stenosis with contralateral carotid occlusion.
METHODS: A retrospective review was conducted to identify a cohort of patients undergoing both carotid duplex and CTA with complete unilateral carotid occlusion between 2000 and 2009. CTA was used to obtain diameter and cross-sectional area measurements of carotid stenosis. Percent stenosis was calculated using the NASCET technique with both diameter and cross-sectional area measurements. Pearson’s correlation coefficients were generated to detect congruency between duplex velocity, diameter-derived stenosis, and cross-sectional area-derived stenosis.
RESULTS: A total of 20 patients were included. Correlation coefficients for diameter-based stenosis were: r=0.698 (p=0.001) for <50% stenosis, r=0.375 (p=0.103) for 50% to 79% stenosis, and r=0.490 (p=0.028) for ≥ 80%. Correlation coefficients for cross-sectional area measurement were: r=0.903 (p< 0.001) for <50% stenosis, r=0.802 (p<0.001) for 50% to 79% stenosis, and r=0.866 (p<0.001) for ≥80% stenosis.
CONCLUSIONS: In the setting of contralateral carotid artery occlusion, duplex ultrasound had a higher correlation with cross-sectional area-derived stenosis than with traditional diameter-derived measurements on CTA. For this subgroup of patients, cross-sectional area measurements may be more reflective of the duplex-derived data due to the ability of CTA to delineate more complex carotid bulb anatomy. Additional studies are needed to correlate cross-sectional data and clinical outcomes.
AUTHOR DISCLOSURES: A. Carnicelli, Nothing to disclose; A. Chandra, Nothing to disclose; A. J. Doyle, Nothing to disclose; D. Gillespie, Nothing to disclose; B. Jahromi, Nothing to disclose; J. Kim, Nothing to disclose; M. Singh, Nothing to disclose; J. Stone, Nothing to disclose.
Posted April 2012