[摘要] 目的 通过对双能X线骨密度仪(DXA)精确度和准确度长期的跟踪研究，进一步证实质量控制在临床测量、药物观察和科研等项工作中的重要意义。方法 测定GE LUNAR DPX-L运行8年前后精确度和准确度变化；DPX-L和PRODIGY不同系列DXA体外和体内测量精度比较；同一台PRODIGY DXA移机前后精确度比较。结果 1995年6月起对腰椎体模L2~4测定平均值为(1.240±0.004)g/cm2,CV%=0.34%，2003年11月起测定的平均值为(1.234±0.009)g/cm2,CV%=0.73%，比1995年比较下降约0.5%，标准差和变异系数均增大1倍多。1995年准确度误差为0.27%。2003年准确度误差为0.72%，误差增大2倍多。2002年8月DPX-L基线测量，L2~4 BMD平均值为(1.206±0.007)g/cm2，CV%=0.67%;2004年7月PRODIGY基线值为(1.250±0.005)g/cm2，CV%=0.42%。DPX-L在腰椎、股骨颈、Word’s区、大转子各部位精确度分别为0.008 g/cm2，0.009 g/m2，0.021 g/m2，0.021 g/cm2;PRODIGY在各部位精度值分别为0.004 g/cm2，0.006 g/cm2，0.013 g/cm2，0.012 g/cm2,PRIDIGY体外和体内精度均优于DPX-L DXA。PRODIGY移机前25次测定的L1~4平均值为(1.188±0.013)g/cm2,2006年1月移机后测定的值为(1.193±0.036)g/cm2,移机前后测量精度有所下降并且基线测定值变化达0.42%。结论 DXA在运行中随着仪器老化、维修等多种因素都会引起精确度和准确度变化，严格进行质量控制是做好临床诊断和研究等各项工作的前提和保证。

    [关键词] 骨质疏松；双能X线骨密度仪；质量控制

    Clinical application research on quality control of DXA

    YAN Jue，CUI Xia，QIN Lin-lin.Nuclear Department,China-Japan Friendship Hospital,Beijing 100029,China

    [Abstract] Objective Through more than ten years research on quality control of DXA the important signification was further confirmed in this work.Methods The precise and accuracy were separately measured of GE LUNAR DPX-L DXA in Jun 1995 and Nov 2003.Two results were compared.The precise results of in vitro and in vivo of DPX-L and PRODIY DXA were measured and compared.The precise was measured before and after moving PRODIGY DXA.Results Mean value of L2~4 BMD(bone mineral density)was (1.240±0.004)g/cm2,CV%=0.34%,accuracy error was 0.27% in 1995.Mean value of L2~4 BMD was (1.234±0.009)g/cm2,CV%=0.67%,accuracy error was 0.72% in 2003.The base line of DPX-L was (1.206±0.009)g/cm2,CV%=0.67% in 2002;in vivo precise at lumber,neck,Ward’s and trenchant were 0.008,0.009,0.021 and 0.021 g/cm2,the base line of PRODIGY was (1.206±0.009)g/cm2,CV%=0.67% in 2004;in vivo precise at lumber,neck,Ward’s and trenchant were 0.004,0.006,0.013 and 0.012 g/cm2.The mean value L1~4 BMD was (1.188±0.013)g/cm2 before moving PRODIGY DXA in Dec 2005,then mean value L1~4 BMD was (1.193±0.036)g/cm2 after moving PRODIGY DXA in Jan 2006.Conclusion Many factors lead to verity of precise and accuracy of DXA,such as long time run,pats old,moving and repair of DXA etc.So quality control of DXA is important guarantee of clinical diagnosis,osteoporosis treatment,medicine and science research work. ......