CT对比剂跟踪技术在静脉血栓栓塞病中的应用

The Application of CT Contrast agent Tracking in Venous Thromboembolism

目的探讨两次对比剂跟踪触发技术在肺动脉及双下肢深静脉CT联合成像诊断静脉血栓栓塞病(VTE)中的可行性。方法搜集临床拟诊肺动脉和(或)下肢静脉血栓患者106例,共120次CT检查,全部采用对比剂跟踪技术,通过跟踪上腔静脉(阈值均为80 HU)及下腔静脉(按阈值为130 HU、140 HU、150 HU及160 HU随机平均分为四组)的方法,分别进行肺动脉和下肢静脉CT联合成像,对靶血管CT值和图像质量进行观察。计量资料采用方差分析(SNK-q检验),等级资料采用秩和检验(Nemenyi),各组间行两两比较。结果肺动脉图像1级97.5%,2级1.7%,3级0.8%,无血栓的肺动脉平均CT值约417.4 HU,而下肢静脉成像中130 HU组与140 HU组,150 HU组与160 HU组无统计学意义(P>0.05),但其他组间互为比较有统计学意义,且150 HU组与160 HU组图像优秀率分别高于130 HU和140 HU组,差异显著,有统计学意义(P<0.01)。结论两次对比剂跟踪触发技术操作简便,可运用于肺动脉及双下肢深静脉联合成像,并将触发点设为下腔静脉,阈值设定为150 HU或160HU,是256层螺旋CT对比剂跟踪触发技术下肢静脉成像的较好条件参数。

Objective To explore the feasibility of dual contrast agent tracking trigger technique in the diagnosis of ve-nous thromboembolism by the combination imaging of pulmonary artery and deep vein CT of both lower limbs.Methods 106 patients suspected of pulmonary artery and/or lower limb venous thrombosis were selected for clinical diagnosis,a total of 120 CT examinations were performed.In all cases contrast tracking technology was implemented.The superior vena cava(both threshold 80 HU)and inferior vena cava(randomly divided into four groups according to threshold values 130 HU,140 HU,150 HU and 160 HU,respectively)were tracked.CT images of pulmonary artery and lower extremity vein were carried out,and CT values of target vessels and image quality were evaluated and analyzed.The measurement data was test-ed by SNK-q test,and the rank sum test(Nemenyi)was used for the comparison of multi-samples.Results Pulmonary artery image levelⅠis 97.5%,levelⅡ1.7%,levelⅢ0.8%,respectively,the average CT value of pulmonary artery with-out thrombus is about 417.4HU.In contrast,there was no statistically significant difference between the 130 HU group and the 140HU group,the 150 HU group and the 160 HU group in the venous imaging of the lower extremity(P>0.05),but the comparison between the 150 HU group and the 130 HU group is statistically significant,and so is between the 160 HU group and the 140 HU group(P<0.01).Conclusion Dual contrast agent tracking trigger technology is easy to operate and can be used in the combination imaging of pulmonary artery and deep vein of both lower limbs.Furthermore,the trigger point was set as the inferior vena cava,and the threshold was set as 150HU or 160HU,which would be a good condition parameter for the imaging of the inferior vena cava and the lower extremities in the 256 slice CT contrast tracking and trigge-ring technology.