自动曝光技术结合迭代法重建技术对肝脏CT辐射剂量的影响  

Effect of automatic exposure technique combined with iterative reconstruction on radiation dose of liver computed tomography

作　　者：沈仁福 严忠浩 王瑾 

机构地区：[1]宁波明州医院放射科,浙江省宁波市315000

出　　处：《世界华人消化杂志》2017年第35期3155-3160,共6页World Chinese Journal of Digestology

摘　　要：目的评价应用自动曝光技术结合迭代法重建技术对肝脏计算机断层扫描(computed tomography,CT)辐射剂量的影响.方法选择于2016-06/2017-06间在宁波明州医院行肝脏CT增强扫面和重建检查的69例患者,采用随机数表法将患者分为对照组、A组和B组,对照组采用常规滤波反投影技术进行重建,A组使用自动曝光技术,B两组采用自动曝光联合迭代重建模式(迭代次数3次).比较3组患者CT图像中不同部位的CT值、主观评价、客观评价和患者接受的辐射剂量.结果 3组患者CT图像中肝实质、门静脉和椎旁肌等部位的CT值间不存在明显的统计学差异(P>0.05).A组和B组患者CT图像的图像噪声、小解剖结构的可视性、像素化表现和整体诊断信心等主观质量评价指标均明显高于对照组(P<0.05),其中,B组的评分明显高于A组(P<0.05).A组和B组患者CT图像噪声强度明显低于对照组,信噪比和对比噪声比明显高于对照组,其中B组较A组更为显著(P<0.05).A组和B组患者的辐射剂量分别为8.57 mSv±0.86 mSv和6.92 mSv±0.51 mSv,明显低于对照组患者的11.32 mSv±1.01 mSv(P<0.05).结论在肝脏CT检查中应用自动曝光技术结合迭代法重建技术能够明显提高图像质量,有效降低患者的辐射剂量.AIM To observe the effect of automatic exposure technique combined with iterative reconstruction on radiation dose of liver computed tomography（CT）. METHODS From July 2016 to July 2017, 69 patients who underwent liver enhanced CT examinations were randomly divided into control group, group A, and group B（23 cases in each group）, in which reconstruction was performed using filtered back projection, automatic exposure technique, and automatic exposure technique combined with iterative reconstruction（strength 3）, respectively. The CT values of different parts in CT images, subjective evaluation, objective evaluation, and radiation dose were comparatively analyzed in the three groups. RESULTS There was no significant difference in the CT values of the liver, portal vein, and paraspinal muscles in the three groups（P〈0.05）. The subjective evaluation indexes（such as visibility, pixel performance, and overall diagnostic confidence） of CT images in groups A and B were significantly higher than those of the control group（P〈0.05）, and the scores of group B were significantly higher than those of group A（P〈0.05）. The noise intensity of groups A and B was significantly lower than that of the control group, while the signal to noise ratio and contrast to noise ratio were significantly higher than those in the control group, with group B performing significantly better than group A（P〈0.05）. The radiation doses in groups A and B were 8.57 mSv ± 0.86 mSv and 6.92 mSv ± 0.51 mSv, respectively, which were significantly lower than that in the control group. CONCLUSION In liver CT examination, using automatic exposure technology combined with iterative reconstruction technology can significantly improve the image quality and reduce radiation dose effectively.

关 键 词：肝脏 CT重建 迭代重建 辐射剂量 

分 类 号：R575[医药卫生—消化系统] R816.5[医药卫生—内科学]