Department of Oral Health Science, Oral Imaging Center, KU Leuven, Leuven, Belgium.
Dentomaxillofac Radiol. 2013;42(8):20130145. doi: 10.1259/dmfr.20130145. Epub 2013 Jul 5.
The main purpose of this study was to determine the accuracy of cone beam CT (CBCT) in measuring the trabecular bone microstructure, in comparison with micro-CT. The subobjective was to examine to what extent bone quality assessment is influenced by X-ray tube current and voltage settings as well as soft tissue surrounding the bone.
Eight human mandibular bone samples were scanned using three different clinical exposure protocol within water (W1-3) and without water (NW1-3) by a high-resolution (80 µm) CBCT machine (3D Accuitomo 170(®); Morita, Kyoto, Japan). Subsequently, the samples underwent micro-CT scanning (SkyScan 1174®; SkyScan, Antwerp, Belgium). After image acquisition, similar volumes of interest of the trabecular structures captured with CBCT and micro-CT were aligned with each other. Segmentation was then performed, and the morphometric parameters were quantified within the volumes of interest by CTAn software (CTAnalyser(®); SkyScan, Antwerp, Belgium). Descriptive statistical analyses and multiple comparisons between all protocols were applied in R software.
High positive Pearson's correlation coefficients were observed between CBCT and micro-CT protocols for all tested morphometric indices except for trabecular thickness. No significant differences were observed between all exposure protocols except for trabecular separation. When examining the soft-tissue effect on trabecular bone structures, no significant differences between NW (1-3) and W (1-3) protocols were observed for all variables.
The present study demonstrated the potential of high-resolution CBCT imaging for in vivo applications of quantitative bone morphometry and bone quality assessment. However, the overestimation of morphometric parameters and acquisition settings in CBCT must be taken into account.
本研究的主要目的是确定锥形束 CT（CBCT）在测量小梁骨微观结构方面的准确性，与微 CT 进行比较。次要目的是研究骨质量评估在多大程度上受到 X 射线管电流和电压设置以及骨周围软组织的影响。
使用高分辨率（80μm）CBCT 机（3D Accuitomo 170®；Morita，京都，日本）在水中（W1-3）和无水条件下（NW1-3），对 8 个人下颌骨样本进行三种不同的临床曝光方案扫描。随后，样本进行微 CT 扫描（SkyScan 1174®；SkyScan，安特卫普，比利时）。图像采集后，将 CBCT 和微 CT 捕获的小梁结构的相似感兴趣体积彼此对齐。然后进行分割，使用 CTAn 软件（CTAnalyser®；SkyScan，安特卫普，比利时）在感兴趣体积内量化形态计量参数。在 R 软件中应用描述性统计分析和所有方案之间的多重比较。
除小梁厚度外，所有测试形态计量指标的 CBCT 和微 CT 方案之间均观察到高度正 Pearson 相关系数。除小梁分离外，所有曝光方案之间均未观察到显著差异。在检查软组织对小梁骨结构的影响时，对于所有变量，NW（1-3）和 W（1-3）方案之间均未观察到显著差异。
本研究表明，高分辨率 CBCT 成像具有用于定量骨形态计量学和骨质量评估的体内应用的潜力。然而，必须考虑到 CBCT 中形态计量参数和采集设置的高估。
