Comparative Analysis Of The Accuracy Of Color Doppler Ultrasound And CTA,DSA In The Diagnosis Of Carotid Artery Stenosis

Objective:The purpose of this study was to compare the results of the same diagnosis by color Doppler ultrasound(abbreviated as ultrasound),CTA and DSA in the diagnosis of carotid stenosis.The results were evaluated by DSA results.And the accuracy,sensitivity,specificity and consistency of the CTA results with the DSA results and the consistency of the CTA results with the DSA results,to assess whether ultrasound and CTA can be used as a reliable diagnosis of carotid stenosis Based on the judgment,whether ultrasound or CTA can replace DSA as a criterion for diagnosing carotid stenosis.Methods:1 Patients who underwent ultrasound and CTA examinations within 2 weeks from January 2015 to December 2018 in our hospital for further definitive diagnosis of DSA or patients undergoing vascular intervention after ultrasound and CTA were collected.Imaging data and radiographic and DSA examinations were performed to review the imaging data of other vascular stenosis in patients with CTA.2 Taking the results of DSA as a reference for diagnosis,comparing the accuracy,sensitivity and specificity of ultrasound and CTA in different degrees of stenosis,and then analyzing the results according to the results of ultrasound and CTA.3 Stenosis calculation formula The degree of carotid stenosis was calculated according to the European Carotid Surgery Study(ECST)method and the North American Symptomatic Carotid Endarterectomy(NASCET)method: degree of stenosis(%)=(1-stenosis diameter / Distal normal lumen diameter)X100%.Grading criteria: mild stenosis(<50%),moderate stenosis(50-69%),severe stenosis(70-99%),complete occlusion.Ultrasound diagnostic criteria refer to the ultrasound diagnostic criteria recommended by the American Radiation Oncology Conference.(1)Normal: The internal systolic peak velocity of the internal carotid artery is <125 cm/s,the end-diastolic flow velocity is <40 cm/s,and the ratio of the internal carotid artery to the common carotid artery peak flow rate is <2.0.(2)stenosis <50%: peak flow rate during systole is 125-230 cm/s,end-diastolic flow rate <40 cm/s,ratio of peak internal carotid artery to common carotid artery <2.0;(3)stenosis 50%-69% The peak systolic velocity was 230 cm/s,the end-diastolic flow rate was 40-100 cm/s,and the ratio of the internal carotid artery to the common carotid artery was 2.0-4.0.(4)Stenosis >70%: systolic peak flow rate >230 cm/ s,end-diastolic flow rate >100cm / s;ratio of peak internal flow velocity of the internal carotid artery to the common carotid artery > 4.0;(5)basic occlusion: visible severe stenosis lumen,the peak flow rate can be very high,very low or not detected;(6)Complete occlusion: no lumen and blood flow were seen.4 Kappa test method was used to evaluate the degree of consistency between ultrasound and DSA and CTA and DSA respectively.When the Kappa value is ?0.75,the agreement between the two is better.When 0.4?Kappa value is <0.75,the two are consistent.Generally speaking,when the Kappa value is <0.4,the consistency between the two is poor.Using the above criteria and calculations to compare the accuracy,sensitivity,specificity and consistency of ultrasound and CTA.Results:1 Ultrasound compared to DSA:1.1 With the diagnostic results of DSA as the reference standard,the accuracy,sensitivity and specificity of ultrasound in the mild diagnosis of stenosis are 92.99%,88.67%,98.40%,respectively.It is accurate in the diagnosis of moderate stenosis.The accuracy,sensitivity and specificity were 98.17%,88.24%,and 92.78%,respectively.The accuracy,sensitivity,and specificity in the diagnosis of severe stenosis were 98.17%,95.59%,and 89.29%,respectively.The accuracy,sensitivity and specificity of the results were 99.39%,88.89% and 99.34%,respectively.1.2 In the consistency analysis,the Kappa value of ultrasound and DSA was 0.889>0.75,P<0.05,indicating that the diagnostic results of the two were in good agreement.2 CTA compared to DSA:2.1 With the diagnostic results of DSA as the reference standard,the accuracy,sensitivity and specificity of CTA in the mild diagnosis of stenosis are 98.48%,97.54%,and 98.48%,respectively,which is accurate in the diagnosis of moderate stenosis.The accuracy,sensitivity and specificity were 99.09%,94.12%,and 97.11%,respectively.The accuracy,sensitivity,and specificity in the diagnosis of severe stenosis were 99.09%,94.64%,and 99.63%,respectively.The accuracy,sensitivity and specificity were 100%.2.2 In the consistency analysis: Kappa value of CTA and DSA was 0.794>0.75,P<0.05,indicating that the two were in good agreement.Conclusion:1 With the DSA test results as the reference standard,ultrasound and CTA have higher accuracy,sensitivity and specificity in the diagnosis of carotid stenosis.2 In the consistency analysis,the consistency of the results of ultrasound,CTA and DSA was good,but the consistency of CTA and DSA was higher.3 Therefore,when DSA is not available,both ultrasound and CTA can be used as a reliable basis for carotid stenosis examination,but ultrasound is more suitable for primary screening.CTA results are consistent with DSA,when DSA is not available.The results of the CTA examination can be used as a reference,it is not yet possible to conclude that DSA can be used as a gold standard for the diagnosis of carotid stenosis.