Duplex scanner versus conventional arteriography for carotid artery disease evaluation

In order to evaluate extracranial circulation, Duplex scanning and conventional angiography were performed. The group of 41 patients (mean age 53.8 +/- 11.8, 71% male) were examined. Results were analyzed for extracranial disease presence such as presence of vessel stenosis (mild, moderate, severe), occlusion and presence of plaques. Data from Duplex scanning and carotid arteriography were correlated within the patients in the term of sensitivity and specificity of the methods used. The sensitivity of Duplex scanning for disease presence was 93% and specificity was 83%. For the presence of stenosis, sensitivity was 79% and specificity was 62%. For mild and moderate stenosis (less than 50% of lumen narrowing) sensitivity was 63%, whereas for severe, high-grade stenosis (greater than 50%) and occlusion the sensitivity was 100%. For the plaque presence the sensitivity was 52% and specificity was 73%. A good accordance of plaque findings with both methods was found only in 24% of patients. By Duplex scanner the plaques were discovered in 92% of patients while by arteriography they were found only in 32%. Duplex scanning and conventional arteriography are both accurate methods for determination of the reduction in diameter of carotid arteries (especially in stenosis greater than 50%), whereas Duplex scanning is more accurate for plaque detection and plaque characterisation.