 |
 |
合适的MRI检查序列可以显示兔的椎体和椎间盘病变[13]。正常椎体中脂肪成分较多,水含量较少,在SE序列T1WI图像上信号较高,T2WI信号稍高或等信号。实验组术后第3周,由于平阳霉素对椎体内微血管及血窦的破坏,软骨终板侧椎体缺血后呈无菌性的炎性和水肿反应,骨细胞和基质的缺血后反应也导致局部的水分含量增多;故在T1WI图像上信号降低,T2WI信号升高,尤其在T2加权脂肪抑制序列上椎体中脂肪组织高信号被抑制后,水含量增加引起T2驰豫时间延长,病变椎体组织信号强度会明显高于正常椎体组织,在MR图像上呈现出鲜明对比。本研究通过对实验组第4周T2WI高信号区面积(ST2WI)与病理切片病变区面积(Shistology)的相关性分析,显示两者间存在明显的正相关性(r = 0.965,P < 0.001),因此,MRI对软骨终板侧椎体缺血的诊断可信度较高,尤其T2WI及脂肪抑制T2WI有较高的诊断特异性和敏感性。
本实验通过穿刺终板侧椎体注入平阳霉素,破坏椎体血供诱发腰椎终板及椎间盘退变,不直接损伤软骨终板或椎间盘,比较接近椎间盘的自然退变病程。但是,就如何利用更加合适的MRI扫描序列更清晰显示终板及椎间盘退变过程。增加实验的样本量和更长的观察时间这些问题,还需在以后的实验中进一步完善。
【参考文献】
Benneker LM, Heini PF, Alini M, et al. Vertebral endplate marrow contact channel occlusions and intervertebral disc degeneration[J]. Spine, 2005, 30(2): 167-173.
Kurunlahti M, Kerttula L, Jauhiainen J, et al. Correlation of diffusion in lumbar intervertebral disks with occlusion of lumbar arteries: a study in adult volunteers [J]. Radiology, 2001, 221(3): 779-786.
Ayotte DC, Ito K, Perren SM, et al. Direction-dependent constriction flow in a poroelastic solid: the intervertebral disc valve [J]. J Biomech Eng, 2000, 122(6): 587-593.
Richardson SM, Hoyland JA. Stem cell regeneration of degenerated intervertebral discs: current status [J]. Curr Pain Headache Rep, 2008, 12(2): 83-88.
Hiyama A, Mochida J, Iwashina T, et al. Transplantation of mesenchymal stem cells in a canine disc degeneration model [J]. J Orthop Res, 2008, 26(5): 589-600.
Lee DY, Cho TJ, Kim JA, et al. Mobilization of endothelial progenitor cells in fracture healing and distraction osteogenesis [J]. Bone, 2008, 42(5): 932-941医.学全.在.线网站www.lindalemus.com.
Wang YJ, Shi Q, Lu WW, et al. Cervical intervertebral disc degeneration induced by unbalanced dynamic and static forces: a novel in vivo rat model [J]. Spine, 2006, 31(14): 1532-1538.
崔力扬, 刘尚礼, 丁 悦, 等. 大鼠腰椎间盘针刺退变模型的建立[J]. 中国矫形外科杂志,2007,15(13): 1008-1011.
Wang J, Tang T, Yang H, et al. The expression of Fas ligand on normal and stabbed-disc cells in a rabbit model of intervertebral disc degeneration: a possible pathogenesis [J]. J Neurosurg Spine, 2007, 6(5):425-430.
吴 叶, 侯树勋. 椎间盘退变动物模型研究进展[J]. 国外医学-骨科学分册, 2005, 26(6): 333-336.
Yorimitsu E, Chiba K, Toyama Y, et al. Long-term outcomes of standard discectomy for lumbar disc herniation: a follow-up study of more than 10 years [J]. Spine, 2001, 26(6): 652-657.
戴春娟, 叶祖萍, 牛 军, 等. 低浓度平阳霉素瘤体内注射治疗血管瘤的临床观察[J]. 临床小儿外科杂志, 2007, 6(5): 36-37.
Guillaume B, Francois J, Nelly B, et al. Macrophage activity in infected areas of an experimental vertebral osteomyelitis model: USPIO-enhanced MR imaging—feasibility study [J]. Radiology, 2008, 248(5): 114-123.
