用DXA测量大鼠骨密度和身体成分的精密度

目的:采用双能X线吸收法(DXA)进行大鼠骨密度(BMD)和身体软组织成分测量的精密度试验,探讨DXA对大鼠骨密度和身体软组织成分测量结果的可靠性。方法:对30只SD大鼠进行了DXA二次重复扫描,采用小动物专用软件分别分析大鼠上肢、下肢、躯干、全身等部位的骨密度,以及脂肪(fat)组织、肌肉(lean)组织和fat百分比,计算其精密度(以变异系数的均方根RMS-CV表示)。结果:SD大鼠全身骨密度测量精密度(RMS-CV)为0.9%,最小显著变化值为0.003 g/cm2;大鼠全身软组织成分:脂肪、肌肉组织的含量和fat组织所占软组织的百分比的精密度分别为9.6%、1.3%和9.7%。结论:DXA能较准确测量大鼠全身骨密度和软组织成分。

The study of the precision of bone mineral density and body composition measurement in rats using DXA

Aim: To measure the precision of bone mineral density(BMD)and body composition in rats using dual-energy X-ray absorptiometry(DXA) and evaluate its reliability.Methods:There were 30 rats accepted duplicated DXA BMD and soft tissue(mea-)surements.Special small animal software was used to caculated BMD and fat tissue content,lean tissue content and the percent of fat tissue content in rat's upper limb,lower limb,trunk area,and total body.The precisions(RMS-CV)of each measurement sites were calculated.Results:The precision(RMS-CV)of BMD in rats's total body was 0.9%,the least significant change(LSC)was 0.003 g/cm~2.The precisions(RMS-CV)of fat tissue,lean tissue content and the percent of fat tissue content in rat total body were(9.6%),1.3%and 9.7%,respectively.Conclusion:BMD and body composition measurements in rats' total body with DXA have good precision.