Skedros J G, Bloebaum R D, Bachus K N, Boyce T M
Bone and Joint Research Laboratories, VA Medical Center, Salt Lake City, Utah 84148.
J Biomed Mater Res. 1993 Jan;27(1):47-56. doi: 10.1002/jbm.820270107.
Backscattered electron (BSE) imaging is considered to be a useful technique for determining relative differences in bone tissue density. However, it is not clear how graylevel variations seen in BSE images of bone tissue, which are primarily dependent on the tissue's average atomic number, correlate to tissue density (g/cm3) and mineral content. Simulated bone tissues, ranging from 32-50% mineral by volume, were made by mixing synthetic hydroxyapatite with a simulated organic matrix. This technique allowed mineral content to be varied while mineral composition and crystallography remained constant. The densities of the simulated tissues were determined using Archimedes' principle. Average atomic numbers of the simulated tissues were interpolated from a regression of BSE graylevel against average atomic numbers of pure standard materials. A strong positive correlation was found to exist between mineral content and density (r2 = 0.978) as well as between mineral content and atomic number (r2 = 0.965). The average graylevel in the BSE image also exhibited a positive correlation to mineral content (r2 = 0.965) and density (r2 = 0.923). Graylevel variations in BSE images of simulated bone tissue were shown to be strongly correlated to density and mineral content, but only as a coincidence of their association with atomic number.
背散射电子（BSE）成像被认为是一种用于确定骨组织密度相对差异的有用技术。然而，尚不清楚在骨组织的BSE图像中看到的灰度变化（主要取决于组织的平均原子序数）与组织密度（g/cm³）和矿物质含量之间的关联。通过将合成羟基磷灰石与模拟有机基质混合，制备了体积矿物质含量在32%至50%之间的模拟骨组织。该技术允许在矿物质组成和晶体学保持不变的情况下改变矿物质含量。使用阿基米德原理测定模拟组织的密度。通过对BSE灰度与纯标准材料平均原子序数的回归来插值模拟组织的平均原子序数。发现矿物质含量与密度之间存在强正相关（r² = 0.978），矿物质含量与原子序数之间也存在强正相关（r² = 0.965）。BSE图像中的平均灰度也与矿物质含量（r² = 0.965）和密度（r² = 0.923）呈正相关。结果表明，模拟骨组织的BSE图像中的灰度变化与密度和矿物质含量密切相关，但这仅仅是它们与原子序数关联的一种巧合。
