Lennholm Camilla, Westerlund Anna, Lund Henrik
Angle Orthod. 2023 May 1;93(3):328-334. doi: 10.2319/090922-633.1.
To investigate the validity and reliability of marginal bone level measurements on cone-beam computed tomography (CBCT) images of thin bony structures using various reconstruction techniques, two image resolutions, and two viewing modes.
CBCT and histologic measurements of the buccal and lingual aspects of 16 anterior mandibular teeth from 6 human specimens were compared. Multiplanar (MPR) and three-dimensional (3D) reconstructions, standard and high resolutions, and gray scale and inverted gray scale viewing modes were assessed.
Validity of radiologic and histologic comparisons were highest using the standard protocol, MPR, and the inverted gray scale viewing mode (mean difference = 0.02 mm) and lowest using a high-resolution protocol and 3D-rendered images (mean difference = 1.10 mm). Mean differences were significant (P < .05) at the lingual surfaces for both reconstructions, viewing modes (MPR windows), and resolutions.
Varying the reconstruction technique and viewing mode does not improve the observer's ability to visualize thin bony structures in the anterior mandibular region. The use of 3D-reconstructed images should be avoided when thin cortical borders are suspected. The small difference when using a high-resolution protocol is unjustified due to the higher radiation dose required. Previous studies have focused on technical parameters; the present study explores the next link in the imaging chain.
使用多种重建技术、两种图像分辨率和两种观察模式，研究锥形束计算机断层扫描（CBCT）图像上薄骨结构边缘骨水平测量的有效性和可靠性。
比较了6例人类标本中16颗下颌前牙颊侧和舌侧的CBCT测量值与组织学测量值。评估了多平面（MPR）和三维（3D）重建、标准分辨率和高分辨率以及灰度和反转灰度观察模式。
使用标准方案、MPR和反转灰度观察模式时，放射学和组织学比较的有效性最高（平均差异=0.02mm），而使用高分辨率方案和3D渲染图像时有效性最低（平均差异=1.10mm）。对于两种重建、观察模式（MPR窗口）和分辨率，舌侧表面的平均差异均具有统计学意义（P<0.05）。
改变重建技术和观察模式并不能提高观察者观察下颌前部区域薄骨结构的能力。当怀疑存在薄皮质边界时，应避免使用3D重建图像。由于需要更高的辐射剂量，使用高分辨率方案时的微小差异是不合理的。以往的研究集中在技术参数上；本研究探索了成像链中的下一个环节。
