Department of Small Animal Diseases and Clinic, Institute of Veterinary Medicine, Warsaw University of Life Sciences (WULS-SGGW), 02-787 Warsaw, Poland.
Department of Large Animal Diseases and Clinic, Institute of Veterinary Medicine, Warsaw University of Life Sciences (WULS-SGGW), 02-787 Warsaw, Poland.
Sensors (Basel). 2024 Sep 5;24(17):5774. doi: 10.3390/s24175774.
Bone mineral density (BMD) varies with aging and both systemic and local diseases; however, such evidence is lacking in feline medicine. This may be due to the need for general anesthesia in cats for direct BMD measurements using dual-energy X-ray absorptiometry (DXA) or quantitative computed tomography (QCT). In this study, computed digital absorptiometry (CDA), an indirect relative BMD-measuring method, was optimized to select an X-ray tube setting for the quantitative assessment of the feline knee joint. The knee joints of nine cats were radiographically imaged and processed using the CDA method with an aluminum density standard and five X-ray tube settings (from 50 to 80 kV; between 1.2 and 12 mAs). The reference attenuation of the X-ray beam for ten steps (S1-S10) of the density standard was recorded in Hounsfield units (HU), compared between X-ray tube settings, and used to determine the ranges of relative density applied for radiograph decomposition. The relative density decreased ( < 0.0001) with an increase in kV and dispersed with an increase in mAs. Then, the percentage of color pixels (%color pixels), representing ranges of relative density, was compared among S1-S10 and used for the recognition of background artifacts. The %color pixels was the highest for low steps and the lowest for high steps ( < 0.0001), regardless of X-ray tube settings. The X-ray tube setting was considered the most beneficial when it effectively covered the lowest possible HU ranges without inducing background artifacts. In conclusion, for further clinical application of the CDA method for quantitative research on knee joint OA in cats, 60 kV and 1.2 mAs settings are recommended.
骨密度（BMD）随年龄和全身及局部疾病而变化；然而，猫科医学中缺乏这种证据。这可能是由于需要对猫进行全身麻醉，以便使用双能 X 射线吸收法（DXA）或定量计算机断层扫描（QCT）直接测量 BMD。在这项研究中，计算机数字吸收法（CDA）是一种间接的相对 BMD 测量方法，被优化用于选择 X 射线管设置，以对猫膝关节进行定量评估。用 CDA 方法对 9 只猫的膝关节进行放射成像，并使用铝密度标准和 5 个 X 射线管设置（50-80 kV；1.2-12 mAs）进行处理。在 Hounsfield 单位（HU）中记录密度标准的十个步骤（S1-S10）的 X 射线束参考衰减值，并在 X 射线管设置之间进行比较，用于确定应用于放射照片分解的相对密度范围。相对密度随 kV 的增加而降低（<0.0001），随 mAs 的增加而分散。然后，比较 S1-S10 之间的彩色像素百分比（%color pixels），表示相对密度范围，用于识别背景伪影。%color pixels 对于低步长最高，对于高步长最低（<0.0001），与 X 射线管设置无关。当 X 射线管设置有效地覆盖尽可能低的 HU 范围而不会引起背景伪影时，被认为是最有益的。总之，为了进一步将 CDA 方法应用于猫膝关节 OA 的定量研究，推荐使用 60 kV 和 1.2 mAs 设置。
