Objective

To investigate the feasibility of synchrotron radiation-based phase contrast enhanced micro-computed tomography (SR-PhC-μCT) for imaging of human meniscus. Quantitative parameters related to fiber orientation and crimping were evaluated as potential markers of tissue degeneration.

Design

Human meniscus specimens from 10 deceased donors were prepared using different preparation schemes: fresh frozen and thawed before imaging or fixed and paraffin-embedded. The samples were imaged using SR-PhC-μCT with an isotropic voxel size of 1.625 μm. Image quality was evaluated by visual inspection and spatial resolution. Fiber voxels were defined using a grey level threshold and a structure tensor analysis was applied to estimate collagen fiber orientation. The area at half maximum (FAHM) was calculated from angle histograms to quantify orientation distribution. Crimping period was calculated from the power spectrum of image profiles of crimped fibers. Parameters were compared to degenerative stage as evaluated by Pauli histopathological scoring.

Results

Image quality was similar between frozen and embedded samples and spatial resolutions ranged from 5.1 to 5.8 μm. Fiber structure, including crimping, was clearly visible in the images. Fibers appeared to be less organized closer to the tip of the meniscus. Fiber density might decrease slightly with degeneration. FAHM and crimping period did not show any clear association with histopathological scoring.

Conclusion

SR-PhC-μCT is a feasible technique for high-resolution 3D imaging of fresh frozen meniscus tissue. Further work is needed to establish quantitative parameters that relate to tissue degeneration, but this imaging technique is promising for future studies of meniscus structure and biomechanical response.

中文翻译：

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人类半月板组织的相位对比增强同步加速器显微断层扫描

客观的

探讨基于同步辐射的相位对比增强微型计算机断层扫描（SR-PhC-μCT）对人体半月板成像的可行性。与纤维取向和卷曲有关的定量参数被评估为组织退化的潜在标志物。

设计

使用不同的制备方案制备来自 10 名已故供体的人类半月板标本：成像前新鲜冷冻和解冻或固定和石蜡包埋。使用 SR-PhC-μCT 对样品进行成像，各向同性体素大小为 1.625 μm。通过视觉检查和空间分辨率评估图像质量。使用灰度阈值定义纤维体素，并应用结构张量分析来估计胶原纤维取向。从角度直方图计算半峰面积 (FAHM) 以量化方向分布。卷曲周期由卷曲纤维的图像轮廓的功率谱计算。将参数与通过 Pauli 组织病理学评分评估的退行性阶段进行比较。

结果

冷冻样品和嵌入样品之间的图像质量相似，空间分辨率范围为 5.1 至 5.8 μm。纤维结构，包括卷曲，在图像中清晰可见。纤维似乎在靠近半月板尖端的地方组织得更少。纤维密度可能会随着退化而略有下降。FAHM 和卷曲期与组织病理学评分没有明显关联。

结论

SR-PhC-μCT 是一种对新鲜冷冻半月板组织进行高分辨率 3D 成像的可行技术。需要进一步的工作来建立与组织退化相关的定量参数，但这种成像技术对于未来半月板结构和生物力学反应的研究很有前景。