Correlation between sonographic and angiographic findings of extracranial carotid artery disease.

Comparison between sonographic and angiographic findings of the extracranial carotid arteries were made in 68 patients. We used a Diasonic Duplex Ultrasonograph (DRF 400) which combined a real-time B-mode imaging system and a pulsed-wave Doppler spectral analyser. Continuous-wave Doppler was also used to determine ophthalmic artery flow direction. The findings were classified into four categories: (1) normal or less than 10% stenosis, (2) 10-49% stenosis, (3) 50-99% stenosis, (4) and total occlusion. The agreement between the two tests was 0.53 which meant fair agreement beyond chance by Kappa statistics. When angiograms were used as gold standard, the sensitivity of duplex sonography was above 80% in all categories of stenosis, and the overall accuracy and specificity were above 90% in those stenosis greater than 50% and occlusion. We conclude that duplex sonography, a reproducible noninvasive test, is a safe and cost-efficient screening method which can provide a good correlation with angiograms in detecting extracranial carotid artery disease.