The value of dual-source dual-energy CT angiography in the diagnosis of carotid artery stenosis

Objective Carotid artery stenosis is one of the important causes of ischemic cerebrovascular diseases,for which angiography remains a chief diagnostic option.Dual-source dual-energy CT,as a newly developed technique,has its unique superiority in angiography,but reports have not seen on its application to the diagnosis of carotid artery stenosis.The authors evaluated dual-source dual-energy CT angiography(CTA) in the diagnosis of carotid artery stenosis by comparing it with digital subtraction angiography(DSA).Methods Forty patients first underwent dual-source dual-energy CTA and then DSA of the carotid artery within two weeks.The carotid artery was classified into common carotid artery,extracranial internal carotid artery and intracranial internal carotid artery.Carotid stenosis was rated as mild(≤29%),moderate(30%-69%),severe(70%-99%) and occlusion(100%) in the analyses of CTA and DSA images.The sensitivity,specificity,accuracy,PPV and NPV of CTA in the diagnosis of carotid artery stenosis were calculated with DSA as the reference standard.Results Of 240 vessel segments in 40 patients,CTA displayed 70 with various degrees of stenosis(mild: n = 35,moderate: n = 25,and severe: n = 10) and 170 normal segments,while DSA exhibited 75 with various degrees of stenosis(mild: n = 38,moderate: n = 24,and severe: n = 13) and 165 normal segments.With DSA as the reference standard,the sensitivity,specificity,accuracy,PPV and NPV of CTA in the detection of carotid artery stenosis were 92.0%(69/75),99.4%(164/165),97.1%(233/240),98.6%(69/70),and 96.5%(164/170),respectively.Conclusion Dual-source dual-energy CTA has a high sensitivity in the detection of carotid artery stenosis,which can be used in the screening and diagnosis of carotid artery stenosis as a routine modality.