双光能X射线骨密度仪测量腰椎骨密度不同扫描模式的对比研究

Comparative study of different scan modes of dual-energy X-ray absorptiometry in the detection of bone mineral density for lumbar

目的:探讨在双光能X射线骨密度仪测量腰椎骨密度时不同扫描模式的差异。方法:选取50例临床科室推送的需要进行骨密度检查的患者,进行腰椎和股骨的骨密度测量,采用3种不同模式的扫描方法:A扫描模式,患者身体平躺,选择OneScan(一次性扫描、无需海绵垫块)扫描模式;B扫描模式,患者身体平躺,不选择One Scan扫描模式;C扫描模式,患者下肢放在海绵垫块上,不选择OneScan扫描模式。结果:A、B两种扫描模式所得腰椎的骨密度值对比,第1、2、3、4腰椎及4节腰椎的平均值差异均无统计学意义(t=-0.721,t=-0.153,t=-1.239,t=-1.892,t=-1.469;P>0.05);A、C两种扫描模式所得的骨密度值对比,第2、3、4腰椎及4节腰椎的平均值差异均有统计学意义(t=2.461,t=3.824,t=4.582,t=4.399;P<0.05),第1腰椎无统计学意义(t=-0.006,P>0.05)。结论:采用OneScan扫描模式进行骨密度测量会高估腰椎的骨密度值。

Objective： To investigate the difference of various scan modes of dual-energy X-ray absorptiometry （DXA）in the detection of bone mineral density （BMD） for lumbar. Methods： 50 patients should be detected the BMD of lumbar and thighbone were enrolled in this study. Different three modes were performed to scan them. In A mode, patients lay low and ＂OneScan mode ＂was chosen （one-time scan, without sponge pad）. In B mode, patients lay low and ＂OneScan mode ＂ wasn＇t chosen. In C mode, patients put their lower limbs on the sponge pad and ＂OneScan mode ＂ wasn＇t chosen. Results： There were no significant difference about BMD values of the first, second, third, fourth lumber and all of four lumbers, respectively, between A mode and B mode （t=-0.721, t=-0.153, t=-1.239, t=-1.892, t=-1.469; P〉0.05）. There were significant differences about BMD values on the second, third, fourth lumber and all of four lumbers, respectively, between A mode and C mode （t=2.461, t=3.824, t=4.582, t=4.399; P〈0.05）. While in the same comparison, there was no significant difference about BMD value on the first lumber （t=-0.006, P〉0.05）. Conclusion： OneScan mode don＇t efficiently calibrate the BMD value of the lumbar, and it will overestimate the BMD value of lumbar if the sponge pad isn＇t used to assist this mode.