Detection of internal carotid artery stenosis with duplex velocity criteria using receiver operating characteristic analysis.
BACKGROUND
Duplex ultrasonography is an excellent non-invasive screening tool for carotid artery stenosis. The aim of this study was to evaluate optimal ultrasonographic criteria for determination of internal carotid artery stenosis with reference to digital subtraction angiography.


METHODS
From January 1995 to December 2003, 114 symptomatic patients underwent both duplex ultrasonography and angiography. Seven velocity criteria were compared with angiographic stenosis and receiver operating characteristic curves were used to determine the best cutoff for each criteria.


RESULTS
Internal carotid artery/common carotid artery systolic velocity ratios (PSV ICA/PSV CCA) and systolic internal carotid artery/diastolic common carotid artery ratios (PSV ICA/EDV CCA) were superior to other criteria for diagnosing internal carotid artery stenosis. For 50% stenosis, the best criterion of PSV ICA/PSV CCA was 1.5 [sensitivity 100%, specificity 85%, area under the curve (AUC) 99%], and the best criterion of PSV ICA/EDV CCA was 3.5 (sensitivity 100%, specificity 58%, AUC 99%). For 60% stenosis, the best criterion of PSV ICA/PSV CCA was 2.6 (sensitivity 100%, specificity 94%, AUC 99%), and the best criterion of PSV ICA/EDV CCA was 10.3 (sensitivity 100%, specificity 96%, AUC 99%). For 70% stenosis, the best criterion of PSV ICA/PSV CCA was 3.1 (sensitivity 100%, specificity 91%, AUC 99%), and the best criterion of PSV ICA/EDV CCA was 10.3 (sensitivity 100%, specificity 91%, AUC 99%).


CONCLUSIONS
Our study showed that velocity ratios are superior to other criteria for detecting carotid stenosis. Each laboratory needs to validate its own results.
Chua
Hoe-Chin
HC
Department of Neurology, National Neuroscience Institute, Tan Tock Seng Hospital, Singapore. hoe_chin_chua@nni.com.sg
Sitoh
Yih-Yian
YY
Earnest
Arul
A
Venketasubramanian
N
N
D000368:Aged; D015901:Angiography, Digital Subtraction; D019540:Area Under Curve; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging* / Q000473:pathology; D016893:Carotid Stenosis / Q000145:classification / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012680:Sensitivity and Specificity; D018616:Ultrasonography, Doppler, Duplex