摘要
目的:探讨使用第三代双源CT(DSCT)低管电压、低对比剂用量扫描方案行CT肺动脉成像(CTPA)检查的可行性及其对降低线束硬化伪影的价值。方法:前瞻性将拟行CTPA检查的60例受试者随机分为2组:分别采用常规扫描方案(管电压90kV,对比剂30mL)和双低剂量扫描方案(管电压70kV,对比剂20mL)。记录2组的辐射剂量。测量并计算肺动脉干及其主要分支血管腔内的CT值、信噪比(SNR)、对比噪声比(CNR)、线束硬化伪影指数(AI)。通过五分量表法对图像质量进行主观评估。分别采用Wilcoxon秩和检验和Student独立样本t检验对2组图像的图像质量及AI值进行比较,采用单因素方差分析对各组内不同肺动脉分支间的AI值进行比较。结果:双低组辐射剂量低于常规组。两组间各项客观图像质量指标(CT值、SNR、CNR)的差异无统计学意义(P>0.05)。常规组中右肺动脉(RPA)、右肺上叶肺动脉(RULPA)的AI值高于其它分支(P<0.05),而双低组中两者的AI值明显降低且与其它分支间的差异无统计学意义(P>0.05),RPA和RULPA的AI值在两组间的差异有统计学意义(t=5.38,P<0.01;t=7.82,P<0.01),同时两者在双低组的图像质量评分优于常规组(Z=4.33,P<0.01;Z=4.53,P<0.01)。结论:第三代DSCT双低CTPA扫描方案可行,能显著降低线束硬化伪影对右肺动脉和右肺上叶肺动脉图像质量的影响。
Objective:To explore the feasibility of low tube voltage and low contrast dose CT pulmonary angiography(CTPA)using the third-generation dual-source CT and its application value in reducing the beam-hardening artifacts.Methods:Totally 60 patients underwent CTPA.All patients were randomly divided into 2 groups:standard group[90kV and 30mL contrast media(CM)]and"double-low"group(70kV and 20mL CM).Objective image quality was evaluated by calculating CT attenuation,signal-to-noise ratio(SNR),contrast-to-noise ratio(CNR),and beam-hardening artifact index(AI).Subjective image quality was assessed by five-point scale.Radiation dose was also recorded.The parameters of objective and subjective image quality were compared with Wilcoxon rank sum test and independent-sample t-test.AI of different branches of pulmonary artery in each group was compared by one-way ANOVA test.Results:There was no significant difference(CT value,SNR and CNR)between the two groups in objective image quality(P>0.05).In"double-low"group,radiation dose was significantly lower than that of standard group(P<0.05).The AIs of right pulmonary artery(RPA)and right upper lobe pulmonary artery(RULPA)in standard group were significantly higher than those in"double-low group"(t=5.38,P<0.01;t=7.82,P<0.01).The AIs of RPA and RULPA were higher than those in other branches in standard group,while no difference was found in"double-low"group.The subjective image quality of"double-low"group was also better than that of standard group(Z=4.33,P<0.01;Z=4.53,P<0.01).Conclusion:Low tube voltage and low contrast dose CTPA with third-generation CT can obtain satisfactory image quality and reduce the influence of beam-hardening artifacts in right pulmonary artery and right upper lobe pulmonary artery.
作者
杨萌
张璋
李锋坦
梁蓉
姜英健
任雯
李睿君
李东
YANG Meng;ZHANG Zhang;LI Feng-tan(Department of Radiology,Tianjin Medical University General Hospital,Tianjin 300052,China)
出处
《放射学实践》
北大核心
2018年第4期378-382,共5页
Radiologic Practice
基金
天津市应用基础与前沿技术研究计划重点项目(14JCZDJC57000)
国家自然科学基金青年科学基金资助项目(81301217)
关键词
肺栓塞
体层摄影术
X线计算机
对比剂
Pulmonary embolism
Tomography,X-ray computed
Contrast media
