不同剂量下重建矩阵对定量CT椎体骨密度测量值的影响  

Effect of different reconstruction matrices on vertebral bone mineral density using quantitative CT at different scanning doses

作　　者：王旭[1] 刘磊[1] 刘义军[1] 李贝贝 童小雨 陈安良[1] WANG Xu;LIU Lei;LIU Yi-jun(Departmentof Radiology,the First Affiliated Hospital of Dalian Medical University,Liaoning116011,China)

机构地区：[1]大连医科大学附属第一医院放射科,辽宁大连116011

出　　处：《放射学实践》2023年第12期1593-1598,共6页Radiologic Practice

摘　　要：目的:探讨不同剂量下重建矩阵对定量CT(QCT)椎体骨密度(BMD)测量值的影响。方法:使用联影uCT760 CT机,采用两种剂量水平(管电压120 kVp管电流150或30 mAs)对欧洲标准脊柱体模(ESP)和QCT校准体模进行扫描。基于原始扫描数据,分别采用512×512、768×768、1024×1024三种矩阵进行图像重建。将重建图像传输至QCT-pro工作站进行体模内各椎体(V1、V2、V3)BMD的测量,基于椎体标定值,计算测量值的相对误差(RE),采用单因素方差分析比较不同重建矩阵下椎体骨密度相对误差差异。回顾性将在本院行胸部HRCT和胸部低剂量CT(LDCT)的各45例患者纳入本研究。对所有患者的原始图像分别采用512×512和1024×1024矩阵进行图像重建,然后由两位医师分别独立进行椎体(Th_(12)和L_(1))BMD的测量并采用组内相关系数(ICC)进行一致性检验,采用配对样本t检验比较不同重建矩阵图像上测得的Th 12和L 1椎体的BMD值及两者均值的差异。结果:150和30 mAs两种剂量水平下不同重建矩阵之间ESP体模中V1、V2、V3及V平均的BMD测量值的相对误差的差异均无统计学意义(P>0.05)。相同重建矩阵两种剂量(150和30 mAs)之间V1、V2、V3及V_(平均)的BMD测量值的相对误差的差异无统计学意义(P>0.05)。两位医师测量的患者椎体BMD值的一致性较好(ICC=0.978~0.990>0.75)。不论是HRCT图像还是LDCT图像,512×512和1024×1024两种重建矩阵之间测得的T_(12)和L_(1)的BMD值及两者均值的差异均无统计学意义(P>0.05)。结论:不同重建矩阵对QCT椎体骨密度测量值无显著影响,胸部HRCT和LDCT扫描均可用于筛查骨质疏松症。Objective:To investigate the effect of different reconstruction matrices on vertebral bone mineral density(BMD)using quantitative computed tomography(QCT)at different radiation dose.Methods:The European spine phantom(ESP)and QCT calibration phantom were scanned using two dose levels(tube voltage of 120kVp,tube current of 150 and 30mAs)at a uCT760 CT scanner(United Imaging).Then the raw imaging data were reconstructed using 512×512,768×768 and 1024×1024 matrices,respectively.The reconstructed images were transmitted to the QCT-pro workstation for BMD measurement of each vertebra.By Taking the vertebral phantom calibration values as the contrast,the relative error(RE)of the measurements was calculated,and one-way analysis of va-riance(ANOVA)was used to compare the differences in the RE of vertebral BMD under different reconstruction matrices.Forty-five patients who underwent high resolution CT(HRCT)and low dose CT(LDCT)of the thorax at our hospital were retrospectively recuited,and vertebral BMD measurements were completed on the original images reconstructed with 512×512 and 1024×1024 matrices respectively.Measurements of BMD of the completed QCT vertebrae(Th_(12) and L_(1))were then performed independently by two practitioners in parallel with a consistency test,using a paired-samples t-test to compare the differences in BMD values of Th 12 and L 1 vertebral,and average of both between the two reconstruction matrices.Results:There were no statistical differences in the relative error of BMD measurements of"ESP standard V1,V2,V3 and V average among different reconstruction matrices at 150 and 30mAs dose levels(all P>0.05).The differences in the relative errors of BMD of V1,V2,V3 and V average between 150mAs and 30mAs with the same reconstruction matrix were not statistically significant(all P>0.05).The consistency of vertebral bone density measured by both physicians was good(ICC=0.978~0.990>0.75).No statistically significant difference(P>0.05)in Th_(12)and L_(1)BMD values and average of them were found betwe

关 键 词：定量CT 体层摄影术 X线计算机 重建矩阵 骨密度 椎体 

分 类 号：R814.42[医药卫生—影像医学与核医学] R681.5[医药卫生—放射医学]