Division of Oral Radiology, Department of Oral Diagnosis, Piracicaba Dental School, University of Campinas, Av. Limeira 901, Piracicaba, SP, 13414-903, Brazil.
Department of Oral Health & Medicine, University Center for Dental Medicine Basel UZB, University of Basel, Mattenstrasse 40, Basel, 4058, Switzerland.
Dentomaxillofac Radiol. 2024 Mar 25;53(3):196-202. doi: 10.1093/dmfr/twae004.
To evaluate the feasibility of frozen soft tissues in simulating fresh soft tissues of pig mandibles using cone beam CT (CBCT).
Two fresh pig mandibles with soft tissues containing 2 tubes filled with a radiopaque homogeneous solution were scanned using 4 CBCT units and 2 field-of-view (FOV) sizes each. The pig mandibles were deep-frozen and scanned again. Three cross-sections were exported from each CBCT volume and grouped into pairs, with one cross-section representing a fresh and one a frozen mandible. Three radiologists compared the pairs and attributed a score to assess the relative image quality using a 5-point scale. Mean grey values and standard deviation were obtained from homogeneous areas in the tubes, compared using the Wilcoxon matched-pair signed-rank test and subjected to Pearson correlation analysis between fresh and frozen physical states (α = .05).
Subjective evaluation revealed similarity of the CBCT image quality between fresh and frozen states. The distribution of mean grey values was similar between fresh and frozen states. Mean grey values of the frozen state in the small FOV were significantly greater than those of the fresh state (P = .037), and noise values of the frozen state in the large FOV were significantly greater than those of the fresh state (P = 0.007). Both mean grey values and noise exhibited significant and positive correlations between fresh and frozen states (P < 0.01).
The freezing of pig mandibles with soft tissues may serve as a method to prolong their usability and working time when CBCT imaging is planned.
评估使用锥形束 CT（CBCT）模拟新鲜猪下颌软组织的冷冻软组织的可行性。
对 2 个含有 2 个充满均匀不透射线溶液管的新鲜猪下颌骨进行 4 台 CBCT 机和 2 种视野（FOV）大小的扫描。将猪下颌骨深冷冻并再次扫描。从每个 CBCT 体中导出 3 个横截面并将其分组为对，其中一个横截面代表新鲜的，另一个代表冷冻的下颌骨。3 名放射科医生比较了这些对，并使用 5 分制对相对图像质量进行评分评估。从管中的均匀区域获得平均灰度值和标准差，使用 Wilcoxon 配对符号秩检验进行比较，并对新鲜和冷冻物理状态之间进行 Pearson 相关性分析（α = .05）。
主观评估显示新鲜和冷冻状态下 CBCT 图像质量相似。新鲜和冷冻状态下的平均灰度值分布相似。小 FOV 中冷冻状态的平均灰度值明显大于新鲜状态（P = .037），大 FOV 中冷冻状态的噪声值明显大于新鲜状态（P = 0.007）。平均灰度值和噪声值在新鲜和冷冻状态之间均呈显著正相关（P < 0.01）。
冷冻带有软组织的猪下颌骨可能是在计划进行 CBCT 成像时延长其可用性和工作时间的一种方法。
