Agreement between multi-detector-row CT angiography and US-ECD in quantification of carotid artery stenosis and plaque characterization

The purpose of this work was to evaluate the agreement between ultra-sound echo-color Doppler (US-ECD) and multi-detector-row CT angiography (MDCTA) in the quantification of carotid artery stenosis as well as plaque characterization. From January 2012 to January 2013 forty-five patients who underwent both MDCTA and US-ECD for the study of carotid arteries, were evaluated (33 males, 12 females; age range 43–70 years; mean age of 59.6 years). For all subjects the following parameters were analyzed: stenosis degree by using the NASCET method, plaque morphology (regular versus irregular), type of the plaque (fatty, mixed and calcified) and presence of ulcerations. Statistical analysis was performed to calculate concordance between the two techniques employed. The agreement observed in the quantification of carotid artery stenosis was 94.4% with a kappa value of 0.9306 (95% confidence interval of 0.8612–1.0). In the definition of the type of plaque, the observed agreements were 91.1% and the kappa value was 0.8815 (95% confidence interval: 0.7920–0.9709). In the definition of plaque ulceration, the observed agreements were 88.4% but the kappa value was only 0.325 (95% confidence interval: 0.201–0.449). Agreement observed in the evaluation of plaque morphology was 78.3% with a kappa value of 0.513 (95% confidence interval: 0.452–0.574). We observed a good agreement between US-ECD and MDCTA in the quantification of carotid artery stenosis and the assessment of plaque type. There was, however, a poor agreement in the evaluation of plaque ulceration. The use of US-ECD and MDCTA provides different results in the evaluation of plaque. Our results suggest that information derived from US-ECD should be always critically compared with other diagnostic techniques.