Tahvanainen Päivi S, Lammentausta Eveliina, Pulkkinen Pasi, Tervonen Osmo, Jämsä Timo, Nieminen Miika T
Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland.
Acta Radiol. 2010 Jun;51(5):543-8. doi: 10.3109/02841851003698222.
Bone mineral density (BMD) is usually determined by dual-energy X-ray absorptiometry (DXA). Digital radiography (DR) has enabled the application of dual-energy techniques for separating bone and soft tissue, but it is not clear yet whether BMD information can reliably be obtained using DR.
To determine the ability of dual-energy digital radiography (DEDR) to predict BMD as determined by DXA.
Reindeer femora (n=15) were imaged in a water bath at a typical clinical imaging voltage of 79 kVp and additionally at 100 kVp on a DR system. BMD was determined in four segmented regions (femoral neck, trochanter, inter-trochanter, Ward's triangle) from these images using the DXA calculation principle. BMD results as determined by DEDR were compared with BMD values as determined by DXA.
Significant moderate to high linear correlations (0.66-0.76) were observed at the femoral neck, Ward's triangle, and trochanter between BMD values as determined by the two techniques. The coefficient of variation (CV(RMS)) ranged between 2.2 and 4.7% and 0.2 and 1.8% for DEDR and DXA analyses, respectively.
DXA-based BMD information can be obtained with moderate precision and accuracy using DEDR. In future, combining BMD measurements using DEDR with structural and geometrical information available on digital radiographs could enable a more comprehensive assessment of bone.
骨密度（BMD）通常通过双能X线吸收法（DXA）来测定。数字X线摄影（DR）已使双能技术得以应用于分离骨骼和软组织，但目前尚不清楚能否使用DR可靠地获取BMD信息。
确定双能数字X线摄影（DEDR）预测DXA所测定的BMD的能力。
在DR系统上，对15只驯鹿股骨在典型临床成像电压79 kVp的水浴中成像，并额外在100 kVp下成像。利用DXA计算原理从这些图像中在四个分割区域（股骨颈、大转子、转子间、Ward三角）测定BMD。将DEDR所测定的BMD结果与DXA所测定的BMD值进行比较。
在股骨颈、Ward三角和大转子处，观察到两种技术所测定的BMD值之间存在显著的中度至高度线性相关性（0.66 - 0.76）。DEDR和DXA分析的变异系数（CV(RMS)）分别在2.2%至4.7%和0.2%至1.8%之间。
使用DEDR可以以中等精度和准确度获得基于DXA的BMD信息。未来，将使用DEDR进行的BMD测量与数字X线片上可用的结构和几何信息相结合，能够对骨骼进行更全面的评估。
