低管电压CTA在诊断急性下肢创伤合并血管损伤中的应用价值

The clinical value of low tube voltage CTA in the diagnosis of acute lower extremity trauma with vascular injury

目的:探讨100 kV低管电压CTA(L-CTA)诊断急性下肢创伤合并血管损伤的可行性。方法:30例疑似下肢创伤合并急性血管损伤患者行100 kV L-CTA检查,分析图像质量的客观参数、主观评分以及辐射剂量,对照急诊手术结果评价L-CTA诊断血管损伤的敏感性及准确度。结果:L-CTA组图像质量主观评分均>3分,图像质量良好;对比常规下肢CTA,L-CTA组血管内密度(VD)和噪声增大(P<0.05);信噪比(SNR)和对比噪声比(CNR)差异无统计学意义(P>0.05);L-CTA组容积CT剂量指数(CTDIvol)、剂量长度乘积(DLP)均低于常规组(P<0.05),辐射剂量下降约32%。L-CTA诊断动脉闭塞18例(其中动脉壁断裂2例),动脉狭窄5例,假性动脉瘤4例,动静脉瘘3例;对照急诊手术探查,诊断敏感性100%,诊断符合率90%。结论:急性下肢创伤合并血管损伤患者行100 kV L-CTA检查即能满足诊断需要,又能有效降低辐射剂量。

Objective： To explore the feasibility of 100 kV low tube voltage CTA （L-CTA） in the diagnosis of acute lower limb trauma with vascular injury. Methods： Thirty patients of suspected lower limb trauma with acute vascular injury were examined by L-CTA. Objective parameter, subjective scoring of image quality and radiation dose were analyzed. Compared with the results of emergency surgery, the sensitivity and accuracy of L-CTA in the diagnosis of vascular injury were evaluated. Results： The subjective image quality was good and the scores were all above 3 in the L-CTA group. Compared with conventional CTA of lower extremity, the L-CTA group had an increase in vessel density （VD） and noise （P〈0.05）. There was no significant difference in signal noise ratio （SNR） and contrast noise ratio （CNR） between two groups （P〉0.05）. Volume CT dose index （CTDIvol） and dose length product （DLP） in the L-CTA group were lower than those in the conventional group （P〈0.05）, with the radiation dose decreased by 32%. L-CTA was used to diagnose 18 cases of arterial occlusion, including 2 cases of arterial wall rupture, 5 cases of arterial stenosis, 4 cases of pseudoaneurysm, and 3 cases of arteriovenous fistula. The sensitivity of diagnosis was 100% and the diagnostic coincidence rate was 90%, comparing with the results of emergency surgery. Conclusion： 100 kV L-CTA examination for patients with acute lower limb trauma combined with vascular injury could meet the diagnostic needs and effectively reduce the radiation dose.