不同重建算法对定量CT椎体骨密度测定准确性的影响  

Effect of Different Reconstruction Algorithms on the Accuracy of Quantitative CT Vertebral Bone Mineral Density Measurement

作　　者：郝辉 朱书萌[2] 赵文哲 徐士杰 丁宁宁 杨健 HAO Hui;ZHU Shumeng;ZHAO Wenzhe;XU Shijie;DING Ningning;YANG Jian(Department of Biomedical Engineering,School of Life Science and Technology,Xi’an Jiaotong University,Xi’an 710049,China;Department of Medical Imaging,the First Affiliated Hospital of Xi’an Jiaotong University,Xi’an 710061,China;不详)

机构地区：[1]西安交通大学生命科学与技术学院生物医学工程系,陕西西安710049 [2]西安交通大学第一附属医院医学影像科,陕西西安710061 [3]上海联影医疗科技股份有限公司,上海201800

出　　处：《中国医学影像学杂志》2023年第10期1090-1095,共6页Chinese Journal of Medical Imaging

摘　　要：目的探讨不同重建算法对体模定量CT(QCT)骨密度测定值准确性的影响。材料与方法使用编号145号欧洲腰椎体模,用低剂量与常规剂量扫描方案(120 kVp,参考管电流分别为30 mAs、200 mAs)各扫描10次,每次间隔5 min。原始数据重建算法选择滤波反投影(FBP)、混合迭代(KARL 3D,level=1~9)、深度学习(AIIR,level=1~5)。测定两种剂量下3种重建算法各椎体CT值、QCT骨密度值。采用单因素方差分析评价各椎体CT值、骨密度值间的差异,并比较各组骨密度测量值的相对标准偏差、相对测量误差。结果椎体CT值低剂量(L2:F=5.144,P<0.01;L3:F=3.626,P<0.01)、常规剂量(L1:F=4.726,P<0.01;L2:F=2.190,P=0.011)各算法间比较,差异有统计学意义。CT值KARL算法较FBP、AIIR高且随重建等级增高而增高,AIIR算法CT值相对稳定。骨密度值3种算法测量值与体模标称值相比均较高。骨密度在低剂量(L1:F=4.358,P<0.01;L2:F=9.309,P<0.01;L3:F=9.292,P<0.01)、常规剂量(L1:F=9.356,P<0.01;L2:F=6.853,P<0.01;L3:F=5.513,P<0.01)各算法间比较,差异均有统计学意义。KARL算法骨密度值较FBP、AIIR高,且随重建等级升高测定值升高,AIIR算法骨密度值相对稳定。AIIR算法的相对误差较小,准确度高。结论不同算法重建后体模图像骨密度测定值与标称值虽然存在差异,但均在误差允许范围内。经深度学习重建后的图像测得骨密度值更接近标称值、测量误差小稳定性高。Purpose To investigate the influence of different reconstruction algorithms on the accuracy of bone mineral density measured by quantitative CT.Materials and Methods Lumbar spine phantom No.145 was scanned with low dose and normal dose(120 kVp,reference tube current 30 mAs/200 mAs)for 10 times with an interval of 5 minutes.For raw data reconstruction,the algorithm selected filtered back projection(FBP),hybrid iteration(KARL-3D,level=1-9),and deep learning(AIIR,level=1-5).CT values and bone mineral density values of quantitative CT of each vertebral body with different reconstruction algorithms were measured via two different doses.One-way analysis of variance was used to evaluate the difference of CT value and bone mineral density of each vertebral body.The relative standard deviation and relative measurement error were compared.Results Vertebral CT value was low dose(L2:F=5.144,P<0.01;L3:F=3.626,P<0.01),conventional dose(L1:F=4.726,P<0.01;L2:F=2.190,P=0.011),the difference between algorithms was statistically significant.The CT value of KARL algorithm was significantly higher than that of FBP and AIIR,which increased with the increase of reconstruction grade,and the CT value of AIIR algorithm was relatively stable.Bone mineral density values of FBP,KARL and AIIR were significantly higher than those of the nominal values of the phantom.There was significant difference in bone mineral density between low dose(L1:F=4.358,P<0.01;L2:F=9.309,P<0.01;L3:F=9.292,P<0.01)and conventional dose(L1:F=9.356,P<0.01;L2:F=6.853,P<0.01;L3:F=5.513,P<0.01)groups.The results of KARL were significantly higher than those of FBP and AIIR,which increased with the increase of reconstruction grade,and the AIIR values were relatively stable.AIIR algorithm had smaller relative error,higher accuracy.Conclusion Although there are differences between the measured values of bone mineral density of phantom images reconstructed by different algorithms and the nominal values,the errors are within the allowable range.The measured bone mineral densit

关 键 词：腰椎体模 定量计算机断层扫描 骨密度 重建算法 深度学习 

分 类 号：R816.8[医药卫生—放射医学] R445.3[医药卫生—临床医学]