Department of Radiology, Perking Union Medical College Hospital, Chinese Academy of Medicine Sciences, Beijing, China.
Department of Radiology, Zhejiang Provincial People's Hospital, Zhejiang, Hangzhou, China.
Arch Osteoporos. 2019 Nov 9;14(1):107. doi: 10.1007/s11657-019-0658-2.
Few studies have systematically evaluated the technical aspects of forearm bone mineral density (BMD) measurement. We found that BMD remained stable regardless of the reference point; however, the ROI identified was not always consistent. Our study highlights the importance of using the same reference point for serial measurements of forearm BMD.
Forearm fractures are clinically important outcomes from the perspective of morbidity, health care costs, and interruption of work. BMD of the forearm, as derived by dual-energy x-ray absorptiometry (DXA), is a better predictor of fracture at the forearm compared with BMD measured at other sites. However, very few studies have evaluated the technical aspects of selecting the ROI for forearm BMD measurement. This study aimed to compare the BMD values measured at the 1/3 radius site using three different reference points: the ulnar styloid process, the radial endplate, and the bifurcation of the ulna and radius.
Healthy Chinese patients participating in the control group of an ongoing study at Zhejiang Provincial People's Hospital were recruited for this study. For each patient, a DXA scan (GE Lunar Prodigy) of the forearm was performed and BMD values were separately calculated using each of the three reference points to identify the ROI. Pearson correlation coefficients were calculated to examine the correlation between the BMD measures derived from each reference point. The F test and independent t test were applied for more robust analysis of the differences in the variances and means.
Sixty-eight healthy Chinese volunteers agreed to participate in this study. The root mean square standard deviation (RMS-SD) percentages of BMD values measured at the 1/3 radius site were 2.19%, 2.23%, and 2.20% when using the ulnar styloid process, radial endplate, and the bifurcation of the ulna and radius as the reference points, respectively. Pearson's correlation coefficients for all pairwise comparisons among these three groups were greater than 0.99. F tests and independent t tests showed p values ranging from 0.92 to 0.99. However, we observed that among 10% of patients, choosing an ROI at the ulnar styloid process led to an inability to accurately determine the BMD at the ultra-distal radius.
Given equal ability to determine BMD at the 1/3 radius accurately, the radial endplate or the bifurcation of the ulna and radius should be preferentially selected as the reference point for routine forearm BMD measurements in order to avoid situations in which the ultra-distal radius BMD cannot be determined.
很少有研究系统地评估前臂骨密度（BMD）测量的技术方面。我们发现，无论参考点如何，BMD 都保持稳定；然而，确定的 ROI 并不总是一致的。我们的研究强调了在连续测量前臂 BMD 时使用相同参考点的重要性。
从发病率、医疗保健成本和工作中断的角度来看，前臂骨折是临床重要的结果。与在其他部位测量的 BMD 相比，通过双能 X 射线吸收法（DXA）得出的前臂 BMD 是前臂骨折更好的预测指标。然而，很少有研究评估选择用于前臂 BMD 测量的 ROI 的技术方面。本研究旨在比较使用三个不同参考点（尺骨茎突、桡骨终板和尺桡骨分叉）测量桡骨 1/3 处 BMD 值的差异。
本研究纳入了正在浙江省人民医院参加一项正在进行的研究的对照组的健康中国患者。对每位患者进行前臂 DXA 扫描（GE Lunar Prodigy），并分别使用三个参考点计算每个参考点的 BMD 值以确定 ROI。计算 Pearson 相关系数以检查从每个参考点得出的 BMD 测量值之间的相关性。应用 F 检验和独立 t 检验更稳健地分析方差和均值的差异。
68 名健康的中国志愿者同意参加这项研究。使用尺骨茎突、桡骨终板和尺桡骨分叉作为参考点时，桡骨 1/3 处 BMD 值的均方根标准偏差（RMS-SD）百分比分别为 2.19%、2.23%和 2.20%。三组之间所有两两比较的 Pearson 相关系数均大于 0.99。F 检验和独立 t 检验显示 p 值范围为 0.92 至 0.99。然而，我们观察到在 10%的患者中，选择尺骨茎突作为 ROI 会导致无法准确确定超远端桡骨的 BMD。
在准确确定桡骨 1/3 处 BMD 的能力相等的情况下，应优先选择桡骨终板或尺桡骨分叉作为常规前臂 BMD 测量的参考点，以避免无法确定超远端桡骨 BMD 的情况。
