Diagnostic value of estimated volumetric bone mineral density of the lumbar spine in osteoporosis
Diagnostic value of estimated volumetric bone mineral density of the lumbar spine in osteoporosis
复制标题
腰椎体积骨密度估计对骨质疏松症的诊断价值
DOI：
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发表时间：
1994
影响因子：
6.2
通讯作者：
R. Eastell
中科院分区：
文献类型：
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作者：
N. Peel;R. Eastell
通过双能X线吸收法（DXA）进行的骨密度（BMD）测量是平面测量。通过测量前后位（AP）和侧位投影中的平面BMD，可以通过假设椎体是椭圆柱体来估计体积BMD。三维校正可提高脊柱骨密度测量对骨质疏松症诊断的准确性。本研究的目的是（1）确定与平面测量相比，年龄对体积BMD的影响;（2）评价体积BMD与平面测量相比的诊断准确性。我们研究了26例绝经后骨质疏松性椎体骨折妇女和114例年龄和性别匹配的无椎体骨折的对照组。使用Lunar DPX通过DXA测量腰椎的AP和侧卧位BMD（AP测量的精度误差为0.8%;椎骨L3的侧向测量为6.4%）。在51岁至85岁之间，L3的体积BMD（vol L3）、L3的侧向BMD（lat L3）、L3的AP BMD（AP L3）和L2-4的AP BMD（AP L2-4）分别下降31%、28%、17%和17%。在vol L3、lat L3、AP L3和AP L2-4方面，与对照组相比，BMD降低31、34、23和23%;以Z评分表示，降低分别为-1.36、-1.33、-1.46和-1.47标准差单位。vol L3、lat L3、AP L3和AP L2-4的ROC分析曲线下面积分别为85、86、87和87%。我们的结论是，与年龄匹配的对照组相比，随着年龄的增长和绝经后骨质疏松症，L3椎体的体积和侧向BMD比AP测量值下降更大。然而，通过校正BMC的椎体体积并不能提高诊断的准确性。随着年龄的增长，观察到的更大的降低可能是由于椎体中松质骨的比例高。诊断准确性没有提高可能是因为侧卧位（因此是体积）BMD测量的精度误差很大。这是可能的，估计体积BMD的诊断准确性可能会提高与使用侧仰卧DXA，测量精度误差较低。
Bone mineral density (BMD) measurements by dual‐energy x‐ray absorptiometry (DXA) are planar measurements. By measuring planar BMD in anteroposterior (AP) and lateral projections, it is possible to estimate the volumetric BMD by assuming that the vertebral body is an ellipsoid cylinder. Correction for the third dimension could improve the diagnostic accuracy of spinal BMD measurement in osteoporosis. The aims of this study were (1) to determine the effect of aging on volumetric BMD compared to planar measurements; and (2) to evaluate the diagnostic accuracy of volumetric BMD in comparison to planar measurements. We studied 26 postmenopausal women with osteoporotic vertebral fractures and 114 age‐ and sex‐matched controls without vertebral fractures from a population‐based group. AP and lateral decubitus BMD of the lumbar spine were measured by DXA using a Lunar DPX (precision error for AP measurement, 0.8%; for lateral measurement of vertebra L3, 6.4%). Between the ages of 51 and 85 years the decreases in volumetric BMD of L3 (vol L3), lateral BMD of L3 (lat L3), AP BMD of L3 (AP L3), and AP BMD of L2–4 (AP L2–4) were 31, 28, 17, and 17%, respectively. The decrease in BMD compared to controls in the osteoporotics for vol L3, lat L3, AP L3, and AP L2–4 were 31, 34, 23, and 23%; expressed as Z scores, the decreases were −1.36, −1.33, −1.46, and −1.47 standard deviation units. The areas under ROC analysis curves for vol L3, lat L3, AP L3, and AP L2–4 were 85, 86, 87, and 87%, respectively. We conclude that there is a greater decrease in volumetric and lateral BMD of vertebra L3 than the AP measurements, both with age and in postmenopausal osteoporosis compared to age‐matched controls. However, the diagnostic accuracy was not improved by correcting BMC for vertebral volume. The greater decreases observed with aging may result from the high proportion of cancellous bone in the vertebral body. The lack of improvement in diagnostic accuracy may be because of the large precision error in lateral decubitus (and hence volumetric) BMD measurements. It is possible that the diagnostic accuracy of estimated volumetric BMD may improve with the use of lateral supine DXA, a measurement with lower precision error.