Reid S A, Boyde A
Department of Anatomy and Embryology, University College London, England.
J Bone Miner Res. 1987 Feb;2(1):13-22. doi: 10.1002/jbmr.5650020104.
We report a study to test the feasibility of studying mineral density distributions in bone using the backscattered electron signal in scanning electron microscopy. Samples were human sixth ribs ranging in age from 8 weeks to 59 years, embedded in polymethylmethacrylate (PMMA), cut, polished, and carbon coated. The proportions of pixels falling in a uniform set of gray level slices of the BSE signal were determined using a microcomputer-based image analysis system interfaced directly to the SEM. The amount of high-density bone gradually increased with age at the expense of low-density bone, and there was an associated compression of the range of the mineral density distribution. Age-related differences were noted between the density distributions in the outer and inner rib cortices. The distribution in the inner cortex in neonates was influenced by the inclusion of densely mineralized endochondral bone and cartilage trabeculae formed at the growth cartilage zone. In adults it appeared that greater bone turnover occurred in the outer cortex, perhaps reflecting a differential mechanical loading across the rib. The technique enabled rapid, unbiased discrimination between the bone of neonates, children, and adults.
我们报告了一项研究，旨在测试利用扫描电子显微镜中的背散射电子信号来研究骨矿物质密度分布的可行性。样本为人的第六肋骨，年龄范围从8周至59岁，嵌入聚甲基丙烯酸甲酯（PMMA）中，进行切割、抛光并涂碳。使用直接与扫描电子显微镜相连的基于微型计算机的图像分析系统，确定落在背散射电子信号均匀灰度切片组中的像素比例。高密度骨的量随年龄逐渐增加，以低密度骨为代价，并且矿物质密度分布范围存在相关压缩。在外层和内层肋骨皮质的密度分布之间观察到与年龄相关的差异。新生儿内层皮质的分布受生长软骨区形成的矿化致密软骨内骨和软骨小梁的影响。在成年人中，似乎外层皮质的骨转换更大，这可能反映了肋骨上不同的机械负荷。该技术能够快速、无偏地区分新生儿、儿童和成年人的骨骼。
