目的　探讨双能 X线骨密度仪 (DXA)与定量 CT(QCT)测量骨密度的准确性。方法　用 DXA(前后位扫描 )与 QCT测量 5具猪腰段脊柱中 2 0个椎骨 ,将各自得到的骨密度与对应灰重密度比较 (DXA骨密度对应椎骨灰重密度 ,QCT骨密度对应椎体灰重密度 )。结果　 QCT骨密度与灰重密度线性相关性较好 (松质 r=0 .80 ,皮质 r=0 .79,P<0 .0 1) ,DXA骨密度较差 (r=0 .4 1,P>0 .0 5 )。结论　 QCT测量骨密度较 DXA准确 Objective To investigate the accuracy of dual-energy X-ray absorptiometry (DXA) and quantitative CT (QCT) in measuring bone mineral density. Methods Twenty vertebrae of 5 pigs with lumbar spine were measured by DXA and QCT. The BMD of each vertebra was compared with the corresponding gray-density (DXA BMD, vertebra gray density, QCT BMD) Body gray density). Results There was a linear correlation between QCT BMD and gray to gray density (r = 0.80 in cortex, r = 0.79 in cortex, P <0.01), and BMD in DXA was worse (r = 0.41, P> 0 .0 5). Conclusion QCT is more accurate than DXA in measuring bone mineral density