中国组织工程研究

中国组织工程研究 ›› 2022, Vol. 26 ›› Issue (18): 2874-2880.doi: 10.12307/2022.697

• 骨与关节图像与影像 bone and joint imaging • 上一篇    下一篇

显微CT在兔胫骨骨髓炎建模过程中的应用

李雨帆1，2，林明玥1，2，王晨鑫1，2，张  瑞1，2，李玉宝1，2，陈  立1，邹  琴1，2   

  1. 四川大学，1分析测试中心，2纳米生物材料研究中心，四川省成都市   610064
  • 收稿日期:2021-08-27 接受日期:2021-09-30 出版日期:2022-06-28 发布日期:2022-01-30
  • 通讯作者: 陈立，博士，实验师，四川大学，分析测试中心，四川省成都市 610064 邹琴，博士，副研究员，四川大学，分析测试中心，纳米生物材料研究中心，四川省成都市 610064
  • 作者简介:李雨帆，男，1998年生，四川省成都市人，汉族，在读硕士，主要从事生物材料方向研究。
  • 基金资助:
    四川省重大科技专项(2020ZDZX0008)，项目负责人：邹琴；成都市科技项目(2019-YF05-00020-SN)，项目负责人：邹琴

Application of micro-CT in rabbit tibial osteomyelitis modeling

Li Yufan1, 2, Lin Mingyue1, 2, Wang Chenxin1, 2, Zhang Rui1, 2, Li Yubao1, 2, Chen Li1, Zou Qin1, 2   

  1. 1Analysis and Testing Center, 2Nano-biomaterials Research Center, Sichuan University, Chengdu 610064, Sichuan Province, China
  • Received:2021-08-27 Accepted:2021-09-30 Online:2022-06-28 Published:2022-01-30
  • Contact: Chen Li, PhD, Experimentalist, Analysis and Testing Center, Sichuan University, Chengdu 610064, Sichuan Province, China Zou Qin, PhD, Associate researcher, Analysis and Testing Center, Sichuan University, Chengdu 610064, Sichuan Province, China; Nano-biomaterials Research Center, Sichuan University, Chengdu 610064, Sichuan Province, China
  • About author:Li Yufan, Master candidate, Analysis and Testing Center, Nano-biomaterials Research Center, Sichuan University, Chengdu 610064, Sichuan Province, China
  • Supported by:
    the Major Science and Technology Project of Sichuan Province, No. 2020ZDZX0008 (to ZQ); Chengdu Municipal Science and Technology Project, No. 2019-YF05-00020-SN (to ZQ)

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摘要：

文题释义：
显微CT(Micro-CT)：是一种非破坏性的3D 成像技术，可以在不破坏样本的情况下，对各处骨骼、岩样、牙齿、活体小动物及各种材料等进行高分辨率X射线成像。其可从二维截面及三维重建的多角度直观地对样品进行观察，并对样品密度、孔隙率等进行定量分析，目前已广泛应用于骨组织工程研究中。
骨髓炎：是一种细菌性骨的感染与破坏，常由血源性感染或开放性骨折、手术感染等因素造成。胫骨是开放性骨折最常见的部位，也是最易发生骨感染的部位之一。骨髓炎模型的建立有助于研究者充分理解其病理机制并进行治疗研究，对骨组织工程而言意义重大。

背景：显微CT(Micro-CT)是一种非破坏性的3D成像技术，可以在不破坏样本的情况下清楚地了解样本的内部显微结构，其分辨率极高，空间分辨率达到1-10 μm，部分先进机型甚至达0.25 μm，无论是数据分析还是图像处理，Micro-CT目前都已在骨组织工程研究中被广泛应用。
目的：在兔胫骨骨髓炎建模过程中，以Micro-CT 作为辅助观察工具，分析兔胫骨因炎症产生的结构变化以验证骨髓炎模型是否建立成功。
方法：取新西兰大白兔20只，其中5只作为对照组，其余15只建立右侧胫骨骨髓炎模型，分别在2，4，6周进行影像学表征(n=5)。术后观察兔的进食、作息及伤口愈合情况；采用X射线活体成像检测兔胫骨骨髓炎模型形成过程中的骨组织变化；使用Micro-CT对建模后患肢进行逐层扫描，获得相应断层图像并对其进行三维重建，计算各组样本的骨体积、骨密度等参数。
结果与结论：①大体观察：第4周起可见造模处周围有脓性液体及组织，并出现炎性反应；第6周可见大面积骨质增生；②X射线片观察：随时间推移可见模型组的肿胀程度和骨膜反应愈发严重，死骨形成变多；③Micro-CT分析：断层图像可见，前4周骨质逐渐出现疏松和增生现象；6周后建模成功的兔骨皮质明显被破坏且严重增生，炎症蔓延至骨髓腔；三维重建后可见6周骨髓炎建模兔骨窗周围有大量死骨形成且骨膜反应剧烈，整体明显肿胀，骨质增生严重；内部松质骨结构严重破坏变形，骨小梁大面积破损缺失，且炎症已蔓延至整根胫骨，骨内膜及骨关节面有显著损伤，皮质骨增生且出现空隙；对炎症与正常骨参数进行计算发现，炎症后骨体积均有所上升，皮质骨密度下降，松质骨密度上升；④结果表明，Micro-CT可行断面成像、三维重建及骨参数定量分析，其优势明显弥补了X射线片与大体观察的不足，为骨髓炎相关骨组织工程研究提供了实验依据及新思路。

https://orcid.org/0000-0001-8316-100X (李雨帆) 

中国组织工程研究杂志出版内容重点：人工关节；骨植入物；脊柱；骨折；内固定；数字化骨科；组织工程

关键词: 显微CT, 胫骨骨髓炎, 骨微观结构, 三维重建, 定量分析, 兔

Abstract: BACKGROUND: Micro-computed tomography (micro-CT) is a non-destructive three-dimensional imaging technology, which can clearly observe the internal microstructure of a sample without damaging. Its resolution is very high, and the spatial resolution reaches 1-10 μm, even 0.25 μm in some advanced models. Micro-CT has been widely used for data analysis and image processing in bone tissue engineering research.  
OBJECTIVE: To analyze the inflammation-induced structural changes of the rabbit tibia using micro-CT to verify whether a rabbit model of osteomyelitis is successfully established.
METHODS:  Twenty New Zealand white rabbits were selected, five of which were taken as the control group, and the remaining fifteen rabbits were used to establish the right tibia osteomyelitis model. After modeling, imaging characterization was conducted in the rabbit models (n=5 at each time point) at 2, 4, and 6 weeks. Feeding, pattern of sleeping, and wound healing in rabbits were observed postoperatively. X-ray in vivo imaging was used to detect the changes of bone tissue during the modeling of rabbit tibial osteomyelitis. Micro-CT was used to scan the affected limb layer by layer to obtain the corresponding cross-sectional images, followed by three-dimensional reconstruction. Bone volume and bone mineral density were calculated in each group.  
RESULTS AND CONCLUSION: Gross observation: Purulent liquids and tissues could be found around the modeling site from the 4th week, and inflammatory reactions occurred. Large-area hyperostosis was observed at the 6th week. X-ray imaging observation: the swelling degree and periosteal reaction in the model group became gradually serious over time, and dead bones proliferated a lot. Micro-CT analysis: The cross-sectional images showed that osteoporosis and hyperplasia gradually appeared during the first 4 weeks. After 6 weeks of modeling, the rabbit cortical bone was significantly damaged and seriously proliferated, and inflammation spread to the medullary cavity. Through the three-dimensional reconstructions, a mass of dead bones formed around the bone window at the 6th week, accompanied by severe periosteal reaction, obvious swelling, and serious hyperostosis. Cancellous bone structure was seriously damaged and deformed, and trabecular bones were largely damaged and lost. Notably, the inflammation spread to the whole tibia. In addition, there was significant damage to endosteum and facies articularis ossium, and the cortical bone proliferated with voids. Findings from bone parameter calculation indicated that the bone volume was increased, the cortical bone mineral density was decreased, and the cancellous bone mineral density was increased after inflammation. To conclude, micro-CT can be used for cross-sectional imaging, three-dimensional reconstruction, and quantitative analysis of bone parameters. Micro-CT scan prominently makes up for the shortcomings of X-ray and gross observation, and provides experimental basis and new ideas for bone tissue engineering research related to osteomyelitis.

Key words: micro-computed tomography, tibial osteomyelitis, bone microstructure, three-dimensional reconstruction, quantitative analysis, rabbit

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