Colour duplex flow imaging in carotid arterial disease: correlation with intra-arterial digital angiography

Colour duplex flow imaging is a highly accurate form of non-invasive assessment of the extra-cranial carotid circulation. This method is precise in characterising the degree of carotid stenosis, when compared with intra-arterial digital subtraction angiography. The accuracy of colour duplex in defining mild (1-30%), moderate (31-70%) and severe (71-99%) stenosis was 96%, 95% and 98%, respectively. Sensitivities and specificities were greater than 90% in each category, while positive and negative predictive values ranged from 96% to 100%.