Sacco Sandra M, Saint Caitlin, Longo Amanda B, Wakefield Charles B, Salmon Phil L, LeBlanc Paul J, Ward Wendy E
Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, St Catharines, Ontario, Canada; Centre for Bone and Muscle Health, Brock University, St Catharines, Ontario, Canada.
Centre for Bone and Muscle Health, Brock University, St Catharines, Ontario, Canada; Department of Health Sciences, Faculty of Applied Health Sciences, Brock University, St Catharines, Ontario, Canada.
Bonekey Rep. 2017 Jan 13;6:855. doi: 10.1038/bonekey.2016.87. eCollection 2017.
Long-term effects of repeated i micro-computed tomography (μCT) scanning at key stages of growth and bone development (ages 2, 4 and 6 months) on trabecular and cortical bone structure, as well as developmental patterns, have not been studied. We determined the effect of repetitive μCT scanning at age 2, 4 and 6 months on tibia bone structure of male and female CD-1 mice and characterized developmental changes. At 2, 4 and 6 months of age, right tibias were scanned using μCT (Skyscan 1176) at one of three doses of radiation per scan: 222, 261 or 460 mGy. Left tibias of the same mice were scanned only at 6 months to serve as non-irradiated controls to determine whether recurrent radiation exposure alters trabecular and cortical bone structure at the proximal tibia. In males, eccentricity was lower (<0.05) in irradiated compared with non-irradiated tibias (222 mGy group). Within each sex, all other structural outcomes were similar between irradiated and non-irradiated tibias regardless of dose. Trabecular bone loss occurred in all mice due to age while cortical development continued to age 6 months. In conclusion, repetitive μCT scans at various radiation doses did not damage trabecular or cortical bone structure of proximal tibia in male and female CD-1 mice. Moreover, scanning at 2, 4 and 6 months of age highlight the different developmental time course between trabecular and cortical bone. These scanning protocols can be used to investigate longitudinal responses of bone structures to an intervention.
在生长和骨骼发育的关键阶段（2、4和6月龄）重复进行显微计算机断层扫描（μCT）对小梁骨和皮质骨结构以及发育模式的长期影响尚未得到研究。我们确定了在2、4和6月龄时重复进行μCT扫描对雄性和雌性CD-1小鼠胫骨骨结构的影响，并对发育变化进行了表征。在2、4和6月龄时，使用μCT（Skyscan 1176）对右侧胫骨进行扫描，每次扫描的辐射剂量为以下三种剂量之一：222、261或460 mGy。对同一只小鼠的左侧胫骨仅在6月龄时进行扫描，作为未受辐射的对照，以确定反复辐射暴露是否会改变胫骨近端的小梁骨和皮质骨结构。在雄性小鼠中，与未受辐射的胫骨（222 mGy组）相比，受辐射的胫骨的偏心率较低（<0.05）。在每个性别中，无论剂量如何，受辐射和未受辐射的胫骨之间的所有其他结构结果均相似。由于年龄增长，所有小鼠均出现小梁骨丢失，而皮质骨发育持续至6月龄。总之，不同辐射剂量下的重复μCT扫描并未损害雄性和雌性CD-1小鼠胫骨近端的小梁骨或皮质骨结构。此外，在2、4和6月龄时进行扫描突出了小梁骨和皮质骨不同的发育时间进程。这些扫描方案可用于研究骨结构对干预的纵向反应。
