Oest Megan E, Jones Jeryl C, Hatfield Cindy, Prater M Renee
Research and Graduate Studies, Virginia Tech, USA.
Birth Defects Res B Dev Reprod Toxicol. 2008 Dec;83(6):582-9. doi: 10.1002/bdrb.20177.
Traditional techniques for quantification of murine fetal skeletal development (gross measurements, clear-staining) are severely limited by specimen processing, soft tissue presence, diffuse staining, and unclear landmarks between which to make measurements. Nondestructive microcomputed tomography (micro-CT) imaging is a versatile, well-documented tool traditionally used to generate high-resolution 3-D images and quantify microarchitectural parameters of trabecular bone. Although previously described as a tool for phenotyping fetal murine specimens, micro-CT has not previously been used to directly measure individual fetal skeletal structures. Imaging murine fetal skeletons using micro-CT enables the researcher to nondestructively quantify fetal skeletal development parameters including limb length, total bone volume, and average bone mineral density, as well as identify skeletal malformations. Micro-CT measurement of fetal limb lengths correlates well with traditional clear-staining methods (83.98% agreement), decreases variability in measurements (average standard errors: 6.28% for micro-CT and 10.82% for clear-staining), decreases data acquisition time by eliminating the need for tissue processing, and preserves the intact fixed fetus for further analysis. Use of the rigorous micro-CT technique to generate 3-D images for digital measurement enables isolation of skeletal structures based on degree of mineralization (local radiodensity), eliminating the complications of blurred stain boundaries and soft tissue inclusion that accompany clear-staining and gross measurement techniques. Microcomputed tomography provides a facile, accurate, and nondestructive method for determining the developmental state of the fetal skeleton using not only limb lengths and identification of malformations, but total skeletal bone volume and average skeletal mineral density as well.
用于量化小鼠胎儿骨骼发育的传统技术（大体测量、清晰染色）受到标本处理、软组织存在、染色弥散以及测量时地标不清晰等因素的严重限制。非破坏性微计算机断层扫描（micro-CT）成像技术是一种用途广泛且有充分文献记载的工具，传统上用于生成高分辨率三维图像并量化小梁骨的微观结构参数。尽管此前已将其描述为一种对胎儿小鼠标本进行表型分析的工具，但此前尚未使用micro-CT直接测量单个胎儿骨骼结构。使用micro-CT对小鼠胎儿骨骼进行成像，使研究人员能够非破坏性地量化胎儿骨骼发育参数，包括肢体长度、总骨体积和平均骨矿物质密度，以及识别骨骼畸形。胎儿肢体长度的micro-CT测量结果与传统的清晰染色方法相关性良好（一致性为83.98%），减少了测量的变异性（平均标准误差：micro-CT为6.28%，清晰染色为10.82%），通过无需组织处理减少了数据采集时间，并保留完整的固定胎儿以供进一步分析。使用严格的micro-CT技术生成三维图像进行数字测量，能够根据矿化程度（局部放射密度）分离骨骼结构，消除了清晰染色和大体测量技术中伴随的染色边界模糊和软组织包含的并发症。微计算机断层扫描提供了一种简便、准确且非破坏性的方法，不仅可以通过肢体长度和畸形识别来确定胎儿骨骼的发育状态，还可以确定总骨骼骨体积和平均骨骼矿物质密度。
