Comparation on the relevance of color Doppler ultrasound and digital subtraction angiography in the diagnosis of extracranial internal carotid artery stenosis

Objective To compare the sensitivity,specificity,accuracy of color Doppler ultrasound (DUS) and digital subtraction angiography(DSA) in detection rate of extracranial internal carotid artery atherosclerotic stenosis,and the relevance of the two methods in the diagnosis of stenosis.Methods DUS and DSA were performed on 105 cases of ischemic patients.According to North American Symptomatic Carotid Endarterectomy Trial,extracranial internal carotid artery stenosis was classified into four grades:mild(the diameter reduction50%),moderate (51%～69%),severe(70%～99%),and total occlusion.Results One patient suffered from acute brain infarction after DSA,and the consistency of extracranial internal carotid artery stenosis diagnosed by DUS and DSA was 177(84.3%) in 210 of 105 cases.The sensitivity,specificity and accuracy of DUS to normal extracranial carotid artery were 93.3%,86.8%and 90.0%;to mild extracranial carotid artery stenosis were 60.0%,95.0%and 91.4%;to moderate extracranial carotid artery stenosis were 71.0%,97.9%and 94.3%;to severe extracranial carotid artery stenosis were 81.8%,96.4%and 93.3%;and to extracranial carotid artery occlusion were 90.9%, 100%and 99.5%.Conclusion There is good relevanc between DUS and DSA in the diagnosis of extracranial carotid artery stenosis,the rate of missed diagnosis of mild and moderate stenosis is high.It is necessary to perform DSA at this situation.