Review Article

A Critical Evaluation of Carotid Duplex Scanning in the Diagnosis of Significant Carotid Artery Occlusive Disease

Table 2

(a) 2 × 2 table for calculation of 50% stenosis. (b) Accuracy of carotid duplex for 50% stenosis or greater.
(a)

Carotid duplex findings Gold standard
>50%<50%

>50%955
<50%225

(b)

Sensitivity 97.94%
Specificity 83.33%
Overall accuracy94.49%
Positive predictive value 95.00%
Negative predictive value 92.59%
False positive 16.67%
False negative 2.06%