DUAL X-RAY ABSORPTIOMETRY OF THE LUMBAR SPINE - THE PRECISION OF PAIRED ANTEROPOSTERIOR/LATERAL STUDIES
DUAL X-RAY ABSORPTIOMETRY OF THE LUMBAR SPINE - THE PRECISION OF PAIRED ANTEROPOSTERIOR/LATERAL STUDIES
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DOI：
10.1259/0007-1285-67-799-624
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发表时间：
1994-07-01
影响因子：
2.6
通讯作者：
FOGELMAN, I
中科院分区：
文献类型：
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作者：
BLAKE, GM;JAGATHESAN, T;FOGELMAN, I
仰卧位侧向双 X 射线吸收测定法 (DXA) 有可能提供一种灵敏且精确的方法来测量腰椎椎体内小梁骨量的变化。与早期卧位侧位技术相比，精度提高的一个重要原因是基线补偿的使用，这是一种使用前后位 (AP) 和侧位扫描数据计算侧位骨矿物质密度 (BMD) 变化的算法。本报告基于 12 名女性志愿者（年龄范围 21-56 岁）的扫描检查了仰卧侧位 DXA 的精确度。对每个受试者进行五对 AP/侧向扫描，精度用变异系数 (CV) 表示。对于 AP 扫描，L1-L4 和 L2-L4 BMD 的 CV 均为 0.8%。有（无）基线补偿校正的 L2-L4 外侧椎体、椎体中部和体积 BMD 参数的精度分别为 1.2% (2.1%)、2.4% (3.0%) 和 1.5% (2.5%)。对两种执行基线补偿的方法（称为乘法算法和加法算法）进行了比较，结果显示前者的精度明显更高。比较不同腰椎组合测量侧椎体BMD的精度，L2-L4的精度明显优于L3-L4。当检查单个椎骨时，L3 具有最佳精度，尽管与 L2 和 L4 的差异并不显着。研究证实，采用基线补偿的仰卧位侧向测量椎体 BMD 比卧位法具有更好的精度。这一改进使得纵向跟踪患者成为可能，并且可能允许横向扫描的灵敏度取代 AP 测量的灵敏度。
Supine lateral dual X-ray absorptiometry (DXA) has the potential to provide a sensitive and precise method of measuring changes in trabecular bone mass in the lumbar vertebral bodies. An important reason for the improvement in precision compared with the earlier decubitus lateral technique is the use of baseline compensation, an algorithm which computes the changes in lateral bone mineral density (BMD) using data from both anteroposterior (AP) and lateral scans. This report examines the precision of supine lateral DXA based on scans of 12 female volunteers (age range 21-56 years). Five AP/lateral scan pairs were performed on each subject and precision expressed by the coefficient of variation (CV). For the AP scan the CV for both L1-L4 and L2-L4 BMD was 0.8%. Precision of the L2-L4 lateral vertebral body, mid-vertebral and volumetric BMD parameters with (without) the baseline compensation correction were 1.2% (2.1%), 2.4% (3.0%) and 1.5% (2.5%), respectively. Two methods of performing baseline compensation, referred to as the multiplicative and additive algorithms, were compared and the former shown to give significantly better precision. The precisions of different combinations of lumbar vertebrae for the measurement of lateral vertebral body BMD were compared and the precision for L2-L4 shown to be significantly better than for L3-L4. When individual vertebrae were examined L3 had the best precision although the differences with L2 and L4 were not significant. The study confirmed that supine lateral measurements of vertebral body BMD with baseline compensation give better precision than the decubitus method. The improvement makes it feasible to follow patients longitudinally and may allow the sensitivity of the lateral scan to supersede that of AP measurements.