The Diagnostic Value Of Direct Dual-source Computed Tomography Venography For Lower Extremity Deep Venous In Deep Venous Thrombosis

Objective:1. To analysis the scanning characteristics and technology advantages of direct dual-source computed tomography venography dual-energy examination for deep venous thrombosis of lower extremity.2. To evaluate the concidence of direct dual-source computed tomography venography and Doppler ultrasound examination for the diagnosis of deep venous thrombosis of lower extremity.3. Using the results of digital subtraction angiography as the standard, the diagnostic accuracy of direct dual-source computed tomography venography was evaluated. Methods:1. Patients data:Collect thirty-four patients from Shanxi Academy of Medical Sciences, Shanxi Dayi hospital who were clinically suspected being deep venous thrombosis and inspected by direct dual-source computed tomography venography dual-energy during March, 2013 to September, 2015. And 21 male cases, 13 female cases, age range from 25-65 years old among that group.2. Inspection methods:34 patients were performed by direct dual-source computed tomography venography dual-energy scan. All the patients were taken Doppler ultrasound examination with both two lower extremities and inferior vena cava within one week before or after direct dual-source computed tomography venography dual-energy scan. Nineteen of them were diagnosed by X-ray digital subtraction angiography with unilateral lower extremity deep vein, and accepting interventional therapy.(1). the scan scheme of DSCTV We took Dual energy CT scanning mode, using non-ionic contrast medium iohexol 350Img/ml 40 ml totally, diluted by 0.9 % saline(contrast : saline=1:8). We also took Medrad high-pressure syringe, double cylinder double mode, each injection tube accommodated diluted contrast agent 180 ml, the total flow rate was 3.0ml/s(unilateral speed was 1.5ml/s), injected through bilateral foot dorsal veins, start scanning after 70-80 s delay, the scanning range was from acrotarsium to the diaphragm level which along the vein blood flow to scan.(2). Post-processing method We can obtain two groups of high and low energy data, and mixed thin planes of original image after direct dual-source computed tomography venography dual-energy scan. All data were transmitted to Singo.via post-processing workstation, completed multi-mode image reconstruction analysis through CT Dual Energy, CT vascular, MM Reading and other post processing software.(3). Statistical method All the analysis procedures were completed via Med Calc12.7.0 and SPSS18.0 software. The diagnostic results of DUS and DSCTV were analyzed by Conformance test, and using the results of DSA as the gold standard to evaluate these diagnostic butters.Results:1. There are 442 vein segments were examined in the thirty-four patients, who were clinically suspected being deep venous thrombosis. 254 segment morbid veins were discovered by dual-source computed tomography venography and 233 segment morbid veins were discovered by Doppler ultrasound. Nineteen patients, diagnosed by X-ray digital subtraction angiography, had analysed 133 vein segments. 103 segment morbid veins were discovered by X-ray digital subtraction angiography, 103 segment morbid veins were discovered by dual-source computed tomography venography and 100 segment morbid veins were discovered by Doppler ultrasound.2. The consequence for Conformance test between dual-source computed tomography venography and Doppler ultrasound examination have a high degree of uniformity, Kappa =0.759, P<0.05.3. Using the results of DSA as the gold standard, the sensitivity and specificity of dual-source computed tomography venography detection deep venous thrombosis were respectively: 97.1%, 90%, and the Area Under Curve served as 0.935. Conclusion:1. Direct dual-source computed tomography venography for lower extremity deep venous has a high clinical value in the diagnosis of deep venous thrombosis of lower limb, wherewith its unique scan and post processing technology. It can display bilateral lower extremity deep venous 3D vascular tree alone with a full and large range at the same time, and provide anatomic information,such as bones, muscle, etc. It also can be helpful to analysis the etiology of deep venous thrombosis.2. The consequence for Consistency test between dual-source computed tomography venography and Doppler ultrasound examination have a high degree of uniformity. And the sensitivity and specificity of dual-source computed tomography venography detection deep venous thrombosis were relatively high. It can be used as the preferred method of examination about deep venous thrombosis.3. Dual-source computed tomography venography examination with simple operation, safe and minimally invasive, low dose of contrast agent, easily accepted by patients, and can be widely applied in clinic.