Duplex ultrasound assessment of extra cranial carotid artery disease: its introduction into a radiology department.

Duplex Doppler ultrasound (DDU) is a non-invasive and potentially accurate modality for assessing carotid bifurcation disease. It is however technically difficult and an appreciable learning curve has been identified. To assess the accuracy of DDU upon introduction into a radiology department with experienced sonographers and radiologists we reviewed the first twenty-five (25) cases in patients, having both DDU and carotid angiography. Sensitivity of 95% and specificity of 81% were obtained for differentiating greater or less than 50% internal carotid artery diameter stenosis, and in detection of 80% or greater stenosis sensitivity and specificity were 83% and 100% respectively. We conclude that DDU is accurate when introduced into a department already competent in ultrasonography, with results being achieved similar to those reported from more experienced centres. Our results also support the appropriateness of the applied criteria for grading of carotid stenosis.