Objective: To relate the vertical striations visualized in the deeper layers of articular cartilage by Magnetic Resonance Imaging (MRI) to histological features. Methods: Two knee joints recovered at post-mortem from males in their seventies with no history or visual evidence of joint disease were examined. MR images were obtained in a 4.7 T 400 mm-bore magnet, after which the knees were fixed, sectioned, and examined histologically. Results: High resolution MR showed vertical high/low signal striations with a two to three-fold variation in signal intensity and a periodicity of 0.56 (±0.16 mm), most prominent in weight bearing areas. Histological sections revealed alternating light and dark staining areas with a periodicity of 1.01 ± 0.54 mm in the lower zones of the cartilage, some, but not all of which clearly represented folding. Given that MR will only visualize vertical structures in cartilage aligned at 90 degrees, whereas histology will cut them at varying angles, it is likely that the vertical structures seen by each modality correspond, and that they represent structural heterogeneity in cartilage; perhaps the presence of plates of high collagen and proteoglycan content. Conclusion: The vertical striations seen routinely in the deep zones of hyaline articular cartilage on histological sections are not artefactual; they are likely to represent structural heterogeneity due to the presence of areas of high collagen and high proteoglycan content that exist in weight- bearing areas. This structural heterogeneity may be of great importance to the integrity and function of the cartilage.
展开▼
机译:目的:通过磁共振成像(MRI)将关节软骨深层可视化的垂直条纹与组织学特征联系起来。方法:检查了七名七十多岁的男性死后恢复的膝关节,没有病史或视觉证据表明有关节疾病。 MR图像是在4.7 T 400毫米孔径的磁铁中获得的,然后将膝盖固定,切开并进行组织学检查。结果:高分辨率MR表现出垂直的高/低信号条纹,信号强度有2到3倍的变化,周期性为0.56(±0.16 mm),在承重区域最为突出。组织学切片显示,在软骨下部区域中,交替出现的浅色和深色染色区域的周期为1.01±0.54 mm,其中一些但并非全部清楚地表示折叠。假设MR仅能看到以90度对齐的软骨中的垂直结构,而组织学会以不同的角度切割它们,那么每种模态所见的垂直结构很可能是相对应的,并且它们代表了软骨中的结构异质性。可能存在高胶原和蛋白聚糖含量的平板。结论:在组织切片上常规见于透明关节软骨深部的垂直条纹不是人工的;由于存在于负重区域的高胶原蛋白和高蛋白聚糖含量的区域,它们可能代表结构异质性。这种结构异质性对于软骨的完整性和功能可能非常重要。
展开▼