能谱CT单能量模式与传统单电压扫描模式的相同CT值:体模研究  

Corresponding photon energies in spectral CT and tube voltages in traditional CT using polychromatic X-ray with same CT attenuation values: an in vitro experiment

作　　者：孙记航[1] 刘勇[1] 王东潜 李昊岩 福井利佳 田中功 彭芸[1] SUN Ji-hang LIU Yong WANG Dong-qian LI Hao-yan RIKA Fukui ISAO Tanaka PENG Yun(Department of Radiology, Beijing Children Hospital, Beijing 100045, China)

机构地区：[1]首都医科大学附属北京儿童医院影像中心,北京100045 [2]东京女子医科大学东医疗中心影像科

出　　处：《影像诊断与介入放射学》2017年第2期108-111,共4页Diagnostic Imaging & Interventional Radiology

摘　　要：目的寻找能谱CT(GSI)显示不同碘浓度体模CT值与传统的单电压扫描(TPXI)相同时的单能量值(MEI)。方法应用聚丙烯材料容器型体模装载5、10、15和20 mg I/ml的碘对比剂,分别在空气背景及软组织背景下应用相同放射剂量的GSI扫描及TPXI扫描,TPXI扫描时分别采用80、100、120和140 kVp各采集一遍数据,两种扫描方式使用相同的转速(0.8 s)及Pitch值(0.984)对比剂对应TPXI扫描相同CT值的MEI。结果在TPXI不同的能量80、100、120和140kV下,MEI对应相同碘浓度CT值在空气背景下为52±1.0、58±1.3、62±1.4和66±1.3 keV;在软组织背景下为53±0.8、59±1.0、64±1.0和68±1.0 keV。结论 MEI在不同碘浓度时不同背景下均与TPXI各自kVp有良好的对应关系。Objective To find the corresponding photon energies （keV） in dual-energy spectral CT imaging and tube voltages （kVp） in traditional CT using polychromatic X-ray with same CT attenuation values.Methods A 1.2 cm-diameter polypropylene phantom containing 4 inserts with different iodine concentrations （5,10,15,and 20 mg/ml） was used for both dual-energy spectral CT （fast 80 kVp and 140 kVp switching） and traditional CT with polychromatic X-ray （80 kVp,100 kVp,120 kVp,and 140 kVp tube voltages） at the same radiation dose level.With air or soft tissue as background,the attenuation values of the iodine solutions under different kVp in traditional CT and different keV in dual-energy spectral CT were measured using the same regions of interest at the same level.Results The corresponding values were 52±1.0 keV and 80 kVp,58±1.3 keV and 100 kVp,62±1.4 keV and 120 kVp,66±1.3 keV and 140 kVp with air as background;53-±0.8 keV and 80 kVp,59±1.0 keV and 100 kVp,64±1.0 keV and 120 kVp,68± 1.0 keV and 140 kVp with soft tissue background.The corresponding keV did not change significantly with iodine concentration.Conclusion Monochromatic energy level in spectral CT correlates well with kVp in traditional CT using polychromatic X-ray and is independent of iodine concentration.

关 键 词：双能量CT 能谱分析 体模研究 单能量图像 

分 类 号：R814[医药卫生—影像医学与核医学]