A Comparative Study Of Carotid Ultrasound, CTA And DSA In Assessing The Accuracy Of Carotid Artery Disease

Objective:The aim of this study was to investigate the clinical value in detecting the carotid artery disease with color doppler sonography (CDS), computed tomography angiography (CTA) and digital subtraction angiography (DSA).Materials and Methods:A total of 313 patients with suspected carotid artery disease underwent examination of DSA, partially completed examination of CDS and/or CTA; Sensitivity, specificity, accuracy, youden index, positive likelihood ratio, negative likelihood ratio were calculated in identifying the degree of carotid stenosis and the atherosclerotic morphology plaques for CDS,CTA,CDS unite CTA.The McNemar and Wilcoxon tests and receiver operating characteristic (ROC) curve analysis were used to analysis the difference of diagnostic perfonnances of the three modalities, P<0.05 determine significant differences.Results:1.The degree of carotid stenosis of DSA as the reference standard, the sensitivity of three methods respectively was:CDS 71.9%, CTA 82.6%,CDS+CTA 89.1%; Specificity:CDS 79.7%,CTA 84.9%,CDS+CTA 77.6%; Accuracy:CDS 75.3%,CTA 83.4%,CDS+CTA 86.2%; Misdiagnosis rate:CDS 28.1%, CTA 17.4%, CDS+CTA 10.9%; Missed diagnosis rate:CDS 20.3%, CTA 15.1%, CDS+CTA 22.4%; youden index:CDS 0.516,CTA 0.675,CDS+CTA 0.667; positive likelihood ratio: CDS3.5419,CTA 5.4702,CDS+CTA 3.9777; negative likelihood ratio:CDS 0.3526,CTA 0.2049,CDS+CTA 0.1405; x2:CDS 78.746,CTA 90.199, CDS+CTA81.829;K:CDS0.508,CTA0.648,CDS+CTA0.645;The area under the curve (AUC):CDS 0.758, CTA 0.838, CDS+CTA 0.833; AUC analysis showed a statistically significant difference between DSA and CDS(P=0.027) and CTA (P=0.041),and no statistically significant difference between DSA and CDS+CTA(p=0.442).2. The plaque morphology of CDS as the reference standard, the sensitivity of two methods respectively was:CTA 90.4%,DSA 71.1%;specificity:CTA 96.3%, DSA 98.5%; accuracy:CTA 92.9%,DSA 77.3%;misdiagnosis rate:CTA 9.6%,DSA 28.9%;Missed diagnosis rate: CTA 3.7%, DSA 1.5%; youden index:CTA 0.867, DSA 0.696;positive likelihood ratio:CTA 24.4324,DSA 47.4;negative likelihood ratio:CTA 0.0997,DSA 0.2934;x2:CTA 144.34, DSA 103.22;P value:CTA 0.057,DSA 0.000;K:CTA 0.855,DSA 0.519;The area under the curve (AUC):CTA 0.925,DSA 0.747.AUC analysis showed a statistically significant difference between CDS and DSA(P<0.01),And no statistically significant difference between CDS and CTA (p=0.057).Conclusion:The CDS unite CTA is the most accurate technique for assessing carotid stenosis in the noninvasive examination, with a slightly better performance than CTA(86.2%vs83.4%), far better than CDS (86.2%vs75.3%). Compared with DSA, the consistency of CDS is moderate, CDS unite CTA is higher consistency than CDS, the combination can be widely used to screen the carotid stenosis early. The diagnostic accuracy of CTA is far superior to DSA (92.9% vs77.3%) for identifying the plaque morphology;Comparing with CDS,the consistency of CTA is good.CTA is an important technique for evaluating the carotid arteries dieases.