Lucas K, Nolte I, Galindo-Zamora V, Lerch M, Stukenborg-Colsman C, Behrens B A, Bouguecha A, Betancur S, Almohallami A, Wefstaedt P
Small Animal Hospital, University of Veterinary Medicine Hannover, Foundation, Bünteweg 9, D-30559, Hannover, Germany.
Small Animal Clinic, Faculty of Veterinary Medicine, National University of Colombia, Bogotá, Colombia.
BMC Vet Res. 2017 May 11;13(1):130. doi: 10.1186/s12917-017-1047-y.
Aseptic loosening due to bone remodelling processes after total hip replacement is one common cause for revision surgery. In human medicine, dual-energy X-ray absorptiometry (DEXA) is the gold standard for quantitative evaluation of bone mineral density, whereas in veterinary medicine conventional radiography is used for follow-up studies. Recently, a method has been described using digital X-ray images for quantitative assessment of grey scale values of bone contrast. Therefore, the aim of the present study was to evaluate the correlation of bone mineral density (BMD) measured by DEXA with grey scale values (GV) measured in digital X-ray images (RX50, RX66) ex vivo.
The measured GV in the chosen X-ray settings showed on average a good correlation (r = 0.61) to the measured BMD with DEXA. Correlation between the two X-ray settings was very good (r = 0.81). For comparisons among regions of interests (ROIs) a difference of 8.2% was found to be statistically significant, whereas in the case of RX50 and RX66 differences of 5.3% and 4.1% were found to be statistically significant.
Results indicate that measuring absolute changes in bone mineral density might be possible using digital radiography. Not all significant differences between ROIs detectable with DEXA can be displayed in the X-ray images because of the lower sensitivity of the radiographs. However, direct comparison of grey scale values of the periprosthetic femur in one individual patient during the follow-up period, in order to predict bone remodelling processes, should be possible, but with a lesser sensitivity than with DEXA. It is important that the same X-ray settings are chosen for each patient for follow-up studies.
全髋关节置换术后因骨重塑过程导致的无菌性松动是翻修手术的常见原因之一。在人类医学中，双能X线吸收法（DEXA）是定量评估骨矿物质密度的金标准，而在兽医学中，传统放射摄影用于随访研究。最近，一种使用数字X线图像定量评估骨对比度灰度值的方法被报道。因此，本研究的目的是评估体外通过DEXA测量的骨矿物质密度（BMD）与在数字X线图像（RX50、RX66）中测量的灰度值（GV）之间的相关性。
在所选择的X线设置下测量的GV与通过DEXA测量的BMD平均显示出良好的相关性（r = 0.61）。两种X线设置之间的相关性非常好（r = 0.81）。对于感兴趣区域（ROI）之间的比较，发现8.2%的差异具有统计学意义，而在RX50和RX66的情况下，发现5.3%和4.1%的差异具有统计学意义。
结果表明，使用数字放射摄影测量骨矿物质密度的绝对变化可能是可行的。由于X线片的敏感性较低，DEXA可检测到的ROI之间并非所有显著差异都能在X线图像中显示出来。然而，在随访期间对单个患者假体周围股骨的灰度值进行直接比较以预测骨重塑过程应该是可行的，但敏感性低于DEXA。重要的是，在随访研究中为每个患者选择相同的X线设置。
