双能量CT低剂量成像结合迭代重建技术在超重者冠状动脉成像中的研究  

Low dose dual-energy coronary artery CTA combined with affirmed iterative reconstruction technique for overweight patients

作　　者：肖虎[1] 

机构地区：[1]新疆医科大学第一附属医院CT室,新疆乌鲁木齐830054

出　　处：《实用放射学杂志》2017年第6期617-620,共4页Journal of Practical Radiology

基　　金：新疆维吾尔自治区自然科学基金项目（2013211A083）.

摘　　要：目的 探讨低剂量双能量CT结合迭代重建技术在超重者冠状动脉血管成像中的价值。 方法 对60例受检者行双能量CT低剂量成像，因重建方法分为A组（FBP法），B组（SAFIRE法），同时将单能谱keV分为6个水平（65、70、75、80、85、90 keV）。采用随机区组设计的方差分析比较不同单能谱keV水平各指标，选择最佳keV；比较最佳keV水平的A、B组间CT值、噪声（SD）、信噪比（SNR）、对比噪声比（CNR）及图像评分等。 结果 60例受检者不同keV水平主动脉（左冠状动脉开口处）CT值、SD、SNR、CNR的差异均有统计学意义（P＜0.05）；B组SNR值及CNR值显著高于A组，SD值显著低于A组，差异有统计学意（P＜0.05）；B组中节段评分为优的血管节段比例高，差异有统计学意义（P＜0.05）。辐射剂量指标剂量长度乘积（DLP）为（238.7±30.82） mGy·cm，有效剂量（ED）为（3.3±0.43） mSv。 结论 在低剂量冠状动脉CT血管成像（CTA）的双能量扫描中，使用迭代重建算法结合最佳单能量谱成像能够提高图像质量,其中75 keV为最佳纯化单能谱图像。Objective To evaluate the feasible of dual-energy coronary artery CTA combined with affirmed iterative reconstruction technique for overweight patients. Methods 60 cases underwent dual-energy coronary artery CTA were enrolled in this reasearch. Patients were divided into two groups according to different reconstruction arithmetic model： group A with FBP reconstruction model, while group B with SAFIRE reconstruction model and monoenergetic images from 65 to 90 keV （with increment of 5 keV）. All the data were measured by one doctor worked in CT department for more than 5 years, and the image quality were analyzed and evaluated by two senior radiologists. Randomized block ANOVA analysis was used to compare objective evaluation indices of different monoenergetic images from 65 to 90 keV to get the best keV level.The comparative t-test was applied to ohiective evaluation indices{CT values,SD,SNR, CNR and image quality score） of group A and B and comparative Z2-test was applied to image quality score at the best keV level.Results There were significant differences in CT value, SD,SNR,CNR of different keV images （P〈0.05）.For objective evaluation of image quality, the S NR and CNR of group B were significantly higher than group A, and SD was significantly lower than group A （P〈0.05）. For subjective evaluation of image quality, there were statistically significant difference between group B and group A （P〈0.05）, the segment score of group B was superior to group A. Radiation dose：the DLP value was （238.7±30.82） mGy·cm,and the ED value was （3.3±0.43） mSv.Conclusion SAFIRE combine with purified single spectrum technique can improve the image quality and reduce radiation dose in dual-energy coronary artery CTA,and 75 keV is the best single energy level.

关 键 词：冠状动脉 低剂量 迭代重建 计算机体层成像 

分 类 号：R322.121[医药卫生—人体解剖和组织胚胎学] R814.42[医药卫生—基础医学]