大鼠腰椎骨性终板的MicroCT观察

Study of rat lumbar vertebral endplate via micro computed tomography

目的分析成年大鼠椎体骨性终板结构及随鼠龄变化的情况。方法使用MicroCT对3、9、16个月龄大鼠（各15只）腰椎进行扫描，对椎体终板骨性结构及内部孔道结构进行3D重建并计算骨体积分数（BV／TV）。结果SD大鼠腰椎骨性终板是一层具有孔道的骨性结构，其内部孔道形成一环形的管网结构，腹侧椎体终板Bv／TV显著小于背侧椎体终板；腹侧为79．9％±7．3％，背侧为90．6％±6．2％，P〈0．05；且椎体终板BV／TV随鼠龄增长显著增大。结论大鼠腰椎骨性终板内的孔道结构分布并非杂乱无章，而是由若干环形管道、交通支及腹背侧的主干管道组成的环形管网，此孔道结构为其内部走行的血管提供了通道，其在椎体终板内的体积比例随鼠龄的增长而减小。

Objective To reconstruct the 3-dimensional （3D） models of vertebral endplate and internal canal structure based upon the micro computed tomography （MicroCT） scanning data and clarify the structural characteristics and changes of bone, canals and lumbar vertebral endplates with advancing age in SD rats. Methods Lumbar spines from male SD rats aged 3, 9 and 16 months （ n = 15 each） were subjected to MicroCT scan. Mimics software was used to reconstruct the 3D models of lumbar vertebral endplate and internal canal structure. The bone volume fraction（BV/TV） of endplate was measured by CTAn software. Results The rebuilt 3 D models of vertebral endplate showed that lumbar endplate was a thin layer of bone and the canals within vertebral endplate formed a ring-shaped canal network after reconstruction. Communicating branches existed between the adjacent canals. Every ring-shaped canal connected with tmnk canals lying in the ventral and dorsal portions of endplate. The BV/TV of endplate in the ventral portion was lower than that in dorsal portion （ ventral side： 79.9% ± 7. 3% ; dorsal side： 90. 6% ± 6. 2%, P 〈 0. 05 ） and BV/TV increased with advancing age. Conclusion The canals within rat lumbar vertebral endplate are not haphazard, but regularly arrayed to form a ring-shaped network of many circular canals, communicating branches and ventral and dorsal trunk canals. This canal network provides channels for blood vessels within endplate. The ratio of older rat canals decreases in endplate.