Evaluation Of Severe Subclavian Artery Stenosis By Color Doppler Flow Imagine

Objective:To evaluate diagnostic value of hemodynamic parameters of color Doppler flow imaging (CDFI) for severe (70%-99%) subclavian artery stenosis (SAS).Methods:252patients with suspected SAS,who confirmed by digital subtraction angiography (DSA),were recruited into the study and examined from June2009to December2013.The degree of stenosis was classified as moderate stenosis (50%-69%) or severe stenosis (70%-99%). By using of color Doppler flow imaging, the residual diameter(Dr), peak systolic velocity (PSV1) and end diastolic flow velocity (EDV) at the stenotic vessel segments were recorded.And the original diameter (Do) and peak systolic velocity (PSV2) of relatively normal segments distal to the stenosis were also recorded.The diameter stenosis (1-Dr/Do) and peak velocity ratio (PSV1/PSV2) were calculated; By using the results of DSA as a reference standard, with the analysis of the receiver operating characteristic curve (ROC curves), the diagnostic values and optimal cutoff values for each aforementioned parameter for the evaluation of severe (70%-99%) were obtained.Results:Among the252patients,109of them were diagnosed as severe SAS (70%-99%) and143patients had moderate SAS (50%-69%). The optimal cutoff values for evaluating severe SAS (70%-99%) were PSV1≥343cm/s, EDV≥60cm/s, PSV1/PSV2≥4.0, respectively. The accuracy for diagnosing SAS were PSV1(86.1%), EDV(85.7%), PSV1/PSV2(84.9%) and1-Dr/Do(80.2%). In addition, if PSV1was used in combination with EDV and1-Dr/Do as diagnostic parameters, the accuracy for diagnosing SAS was improved from86.1%to87.3%;If PSV1was used in combination with EDV and PSV1/PSV2as diagnostic parameters, the accuracy for diagnosing SAS reached95.8%.Conclusion:The CDFI hemodynamic parameters of PSV1, EDV and PSV1/PSV2has good consistency with DSA in the diagnosis of severe SAS (70%-99%), and a combination of these three parameters can greatly improve the accuracy for diagnosing SAS.