王鹏程,赵雷,翟小娟,等.数字血管减影中kVp及mAs选择对患者剂量及低对比度血管检出能力的影响[J].中华放射医学与防护杂志,2007,27(4):400-402.WANG Peng-cheng,ZHAO Lei,ZHAI Xiao-juan,et al.Effect of kVp and mAs settings on patient exposure dose and the detecting sensitivity for low contrast blood vessel in digital subtraction angiography[J].Chin J Radiol Med Prot,2007,27(4):400-402
数字血管减影中kVp及mAs选择对患者剂量及低对比度血管检出能力的影响
Effect of kVp and mAs settings on patient exposure dose and the detecting sensitivity for low contrast blood vessel in digital subtraction angiography
投稿时间:2006-07-10  
DOI:
中文关键词:  数字减影  体表入射剂量  影像质量
英文关键词:Digital radiography  Flat panel detector  Exposure dose
基金项目:
作者单位
王鹏程 271016 泰山医学院放射学院 
赵雷 271016 泰山医学院放射学院 
翟小娟 271016 泰山医学院放射学院 
刘伟 271016 泰山医学院放射学院 
张桂芳 苏州大学放射医学与公共卫生学院 
李士骏 苏州大学放射医学与公共卫生学院 
黄永杰 苏州大学放射医学与公共卫生学院 
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中文摘要:
      目的 分析数字血管减影中kVp及mAs设置对患者皮肤剂量、有效剂量及低对比度血管检出能力的影响。方法 以不同浓度碘造影剂自制低对比度血管减影体模,保持影像增强器输入端X射线比释动能为1.1 μGy/帧,改变不同kVp设置,测量体模表面X射线入射剂量ESD,观察影像,确定可检测的最低碘造影剂浓度。管电压保持70 kV,改变mAs设置,测量影像增强器输入端每帧影像所需X射线空气比释动能、体模ESD剂量及可检测的最低碘造影及浓度。以Monte Carlo 模拟程序PCXMC Ⅴ 1.5模拟计算有效剂量。结果 体模ESD及患者有效剂量随mAs呈线性变化。保持影像增强器输入端空气比释动能1.1 μGy/帧,kVp由50变化到100,体模DSA影像可分辨的最低碘造影剂浓度线性增大;保持管电压70 kV,mAs由6.4变化到64,体模DSA影像可分辨的最低碘造影剂浓度按指数规律减小。当曝光量(mAs)超过40后,其对低对比度血管检出的影响不明显。结论 对DSA系统而言,降低X射线机管电压要比增大X射线机输出强度更能有效改善其低对比度血管的检测能力。
英文摘要:
      Objective To investigate the effectiveness of kVp, mAs on patient exposure dose and the detecting sensitivity for low contrast blood vessel in digital subtraction angiography. Methods A DSA phantom with 1.5 mm diameter vessels containing iodine at various concentrations was made. The air kerma 1.1 μGy/frame was kept at the entrance of I.I, with kVp changed to measure ESD and to determine the detectable threshold iodine concentration (DTIC) of the phantom on image displayer.X-ray tube voltage was kept at 70 kV, adjusted mAs and measured air kerma at entrance of I.I, ESD and DTIC. The effect dose was calculated with Monte Carlo simulation program PCXMC Ⅴ 1.5. Results As kVp varied from 50 to 100 kV,while the entrance air kerma of I.I was kept at 1.1 μGy/frame, the ESD and effect dose of patient varied linearly according to mAs. As mAs changed from 6.4 to 64 less than 70 kV, the DTIC decreased exponentially, while as the exposure exceed 40 mAs,the improvement of DTIC become modest. Conclusions Reduction of the X-ray tube voltage instead of increase of the exposure level would improve the DSA system performance. As the entrance air kerma of I.I exceed 2.5μGy/frame,increasing exposure may not improve the image quality.
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