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目的 建立兔颈脊髓半侧挫伤模型,观察不同程度损伤24小时后其MRI及组织学表现.方法 22只成年雄性新西兰兔,随机分为中度损伤组(n=9)、重度损伤组(n=9)和假手术组(n=4).直径为3.0 mm的打击头由电磁伺服材料试验机驱动,对准C5脊髓左侧行高速挫伤(500 mm/s).根据打击头的位移距离分为位移2.0 mm组(中度损伤组)和位移2.8 mm组(重度损伤组).假手术组仅暴露C5脊髓,不进行挫伤.损伤后24小时每组随机取两例行MRI影像学检查,所有动物均取材进行组织学观察,测量横断面脊髓出血面积.结果 中度损伤组打击力和位移分别为(2.47±0.39)N和(1.99±0.02)mm,重度损伤组打击力和位移分别为(5.16±0.82)N和(2.76±0.02)mm,中度损伤组的打击力明显小于重度损伤组(P<0.05).MRI结果显示,中度及重度损伤组均可见C5左侧脊髓信号改变.HE染色显示脊髓左侧有明显的出血及脊髓组织结构破坏,中度损伤组损伤中心横截面出血面积(0.012±0.006)mm2明显小于重度损伤组(0.039±0.006)mm2(P<0.05).结论 本文建立的兔颈脊髓半侧挫伤模型能够控制挫伤位移,实现对脊髓的高速打击.不同程度的颈脊髓半侧挫伤在打击力、MRI影像学及组织学上均有不同.“,”Objective To establish a unilateral cervical spinal cord contusion injury model in rabbits, and characterize the MRI and histology of two-level spinal cord contusion at 24 hours after injury. Methods Twenty-two male New Zealand rabbits were randomly assigned into the moderate lesion group (n=9), the severe lesion group (n=9) and the sham group (n=4), respectively. All animals in the moderate group were subjected to 2.0 mm contusion at 500 mm/s on the left of C5 spinal cord, while all animals in the severe group to 2.8 mm contusion. The flat head impactor was 3.0 mm in diameter and was driven by an electromagnetic-servo material testing machine. The sham group exposed the spinal cord without contusion. Post-injury MRI was scanned and analyzed for 2 animals per group. Spinal cord samples of all animals were harvested 24 hours after injury, and analyzed the hemorrhagic area of the cord on cross section of the epicenter. Result The peak force and actual contusion displacement were (2.47 ± 0.39) N and (1.99 ± 0.02) mm in the moderate group, and (5.16 ± 0.82) N and (1.99 ± 0.02) mm in the severe group, respectively. There was significant difference in the peak force between groups (P<0.05). There were high and low intensity T2-weighted signal in the C5 cord on post-operative MRI in the two injured groups. Histological analysis showed that there were hematoma and tissue damage on the left side of spinal cord in two injured groups, and hHematoma area was (0.012 ± 0.006) mm2 in the moderate group and (0.039 ± 0.006) mm2 in the severe group. There was significant difference in hematoma area between groups (P<0.05). Conclusion The study establishes a unilateral cervical spinal cord contusion model with displacement control and at high speed. Different unilateral cervical spinal cord contusions showed different degrees of lesions in peak force, MRI and histology.