DXA仪测量骨密度的质量控制及效果评价  

Quality control and evaluation of bone densitometry by DXA

作　　者：秦莹[1] 尚家芸[2] 唐成志[3] 孙蕾[2] 杨定焯[2] 赵立强[1] 

机构地区：[1]610041,成都 四川大学华西公共卫生学院 [2]四川大学华西第四医院骨质疏松科, 成都610041 [3]四川大学华西第四医院门诊办公室, 成都610041

出　　处：《中华骨质疏松和骨矿盐疾病杂志》2014年第1期55-61,共7页Chinese Journal Of Osteoporosis And Bone Mineral Research

摘　　要：目的分析同一厂家生产的不同型号DXA仪及使用不同年限DXA仪测量骨密度(BMD)的质量控制和效果评价。方法 2008年和2012年分别对GE-Lunar制造的的DPX-L仪和Prodigy仪行准确度(accuracy)和精确度(precision)测验。准确度试验仅测试作者自行研制的腰椎体模,精确度试验分别对腰椎体模、女性腰椎和DXA仪自带质量控制体模进行分析。所有测试均按照测量技术要求由同一技师操作。准确度试验为1 d内连续扫描腰椎体模10次,计算BMD测量值与体模真值的百分比。精确度试验分别以腰椎体模、厂家质量控制体模和女性腰椎为对象,每日测量1次,连续25次,计算变异系数(CV)。精确度测试中3个测量对象CV值的计算和应用方法略有差异。结果以BMD为描述指标,2008年DPX-L仪与Prodigy仪BMD准确度误差分别为0.80%和3.80%,差异有统计学意义(P<0.001),Prodigy仪应用4年前后的准确度误差分别为3.80%和3.70%(P>0.05)。DPX-L仪应用15年(至2008年)与Prodigy仪开始应用时(2008年)腰椎体模的精确度误差分别为1.88%和0.33%,差异有统计学意义(P<0.001),DPX-L仪淘汰前精确度误差较Prodigy仪大5.6倍;女性腰椎精确度误差分析显示DPX-L仪的误差较Prodigy仪大4.9倍。结论不同DXA仪及不同使用年限其准确度和精确度均不同,应重点关注不能校正的精确度。短期精确度较长期精确度的干扰因素少,可比性较强。Objective To analyze the quality control and evaluate different types dual X-ray absorptionmetry （ DXA） from the same manufacturer , and the same DXA in the different time of measuring the bone densitometry .Meth-ods Conduct the accuracy and precision tests with DPX-L and Prodigy from GE-Lunar in 2008 and 2012 respectively . Lumbar spine phantom designed by the authors was used in the accuracy tests .In the precision tests , the lumbar spine phantom, female lumbar spine and quality control phantom of the Prodigy were used .All the subjects were tested by the same technician under standard the technical requirements .The accuracy tests scanned the phantom for 10 times consecu-tively on the same day and calculate the percentage of the measured value and true value of bone mineral density （ BMD） . The precision tests scanned the lumbar spine phantom , female lumbar spine and quality control phantom once a day for＆amp;nbsp;consecutively 25 days, and calculate the coefficient of variation （CV）.Results The BMD was used as the description indicator , and the accuracy errors of DPX-L and Prodigy were 0.80% and 3.80% （ P＆lt;0.001 ） in 2008 .The accuracy errors of Prodigy before and after the application were 3.80%and 3.70% （ P＆gt;0.05 ） .The precisions errors of DPX-L （ after the application of 15 years until 2008 ） and Prodigy （ started to use in 2008 ） were 1.88% and 0.33% （ P＆lt;0.001 ） .The precision error of DPX-L was 5.6 times bigger than that of Prodigy .Female lumbar spine scanning showed that the precision error of DPX-L was 4.9 times bigger than that of Prodigy （9.17%/1.89%）.Conclusions The accu-racy and precision errors varies with the different types of DXA and with the different application time of the same DXA . The uncorrectable precision errors should be more concerned .Compared with the long-term precision , the short-term pre-cision had less confounders and stronger comparability .

关 键 词：双能X射线吸收骨密度测量仪 骨密度 准确度 精确度 质量控制 

分 类 号：R681[医药卫生—骨科学]