显微CT设定不同阈值范围对评价生物活性玻璃在体内成骨结果的影响

Setting different thresholds to analyze the osteogenesis of bio-glass in vivo under Micro CT

目的研究显微CT采用不同阈值范围对评价生物活性玻璃植入兔体后成骨结果的影响,探讨阈值范围选择的重要性及解决方法。方法采用新西兰大白兔股骨髁缺损模型,植入生物活性玻璃,3个月后完整取出。采用显微CT对取出的植骨材料进行扫描,分别采用不同阈值范围代表新骨和剩余材料,分为A、B、C、D、E、F 6个实验组,分析不同组之间的新生骨体积百分比及剩余材料体积百分比的差异;显微CT扫描后,将材料制作为不脱钙组织切片,进行Van Gieson染色,用Image-Pro Plus图像分析软件对切片的新生骨百分比进行测量和分析并作为对照组,对实验组与对照组之间进行相关性分析。结果 6个实验组的新生骨体积百分比分别为17.96%±1.23%、20.36%±1.66%、22.04%±2.22%、23.16%±1.34%、26.48%±1.38%、28.91%±2.10%,对照组组织学结果为21.33%±1.25%,相关性分析结果为C组与对照组相关性最高(r=0.867,P<0.05)。结论不同阈值范围分析生物活性玻璃成骨能力具有较大差异,选用骨组织1 200~2 700、剩余材料≥2 700的阈值范围,与组织学结果相关性最高。在研究中需结合组织病理学切片及显微CT类型,选取合适阈值范围,以便采用显微CT进行进一步分析。

Objective To study the effect of different threshold range of micro CT on the evaluation of osteogenesis after bioactive glass implantation in rabbits, and to explore the importance and solution of threshold range selection. Methods A New Zealand white rabbit model of femoral condyle defect was used.Bioactive glass was implanted and removed completely 3 months later. Micro CT was used to scan the bone graft materials, and different threshold ranges were used to represent the new bone and the remaining material, and divided into 6 experimental groups: A, B, C, D, E and F. The differences in the volume percentage of new bone and the volume percentage of the remaining material between different groups were analyzed. After micro CT scanning, the material was made into non decalcified tissue sections and stained with van Gieson. The percentage of new bone in the sections was measured and analyzed with Image Pro Plus image analysis software and used as the control group. The correlation between the experimental group and the control group was analyzed. Results The volume fraction of new bone in 6 experimental groups was 17.96%±1.23%, 20.36%±1.66%, 22.04%±2.22%, 23.16%±1.34%, 26.48%±1.38% and 28.91%±2.10% respectively, and that in the control group was 21.33%±1.25%. The correlation analysis showed that group C had the highest correlation with the control group(r=0.867, P<0.05). Conclusion Different threshold range analysis of bioactive glass has great difference in osteogenic ability, the threshold range of 1 200-2 700 of bone tissue and ≥2 700 of residual material was selected, which had the highest correlation with histological results. Selecting appropriate threshold range in combination with histopathological sections and micro CT types was needed, so as to facilitate further analysis with micro CT.