正常人腰椎骨密度不同测量方法的比较分析

目的比较腰椎骨密度不同测量方法的异同点，旨在为合理地应用各种腰椎骨密度仪。方法应用定量ＣＴ（简称为ＱＣＴ）和双能Ｘ线骨密度仪（简称为ＤＸＡ，其中包括椎体正位测量，简称为ＰＡＤＸＡ；侧位全椎体测量，简称为ＬＤＸＡ；侧位椎体中部测量，简称为ＭＬＤＸＡ）测量了４４３例正常人腰椎的骨密度，其中男１８９例，平均年龄４６．９岁；女２５４例，平均年龄４５．７岁。结果ＱＣＴ和ＰＡＤＸＡ的重复性明显优于ＬＤＸＡ和ＭＬＤＸＡ；年下降率和骨密度线性丢失均以ＱＣＴ最为明显；无论男女，ＱＣＴ峰值出现最早，其次是ＭＬＤＸＡ和ＬＤＸＡ，ＰＡＤＸＡ峰值出现最晚；各种测量方法的相关性与所测的结构是否相似有关。结论腰椎各种骨密度测量方法各有其特点，各种测量方法仍不能互相取代。

Normal changes in spinal bone mineral density: a comparison between different bone densitometries

Objective To appreciate use of different spinal bone densitometry, we compared results of spinal bone mineral density (BMD) measured by quantitative CT (QCT) and dual Xray absorptiometry (DXA) in normal subjects. Methods Four hundred and fortythree healthy subjects (189 males, mean age 46.9 years; 254 females, mean age 45.7 years) were recruited for BMD assessment. BMD was measured by both QCT and DXA, including posteroanterior DXA (PADXA), lateral DXA(LDXA) and midlateral DXA (MLDXA). Results Reproducibility of QCT and PADXA was better than that of LDXA and MLDXA. Bone loss measured by QCT were shown to be more rapid in both annual decrement linear regression than that measured by others. For both genders, BMD values peaked earlier when measured by QCT, followed by MLDXA, LDXA and PADXA. Correlations between different techniques were depended on the structure which the different techniques measured. Conclusions Because of the inherent difference, one method cannot be simply substituted by others.