中文摘要：

目的：探讨兔坐骨神经急性牵拉伤本征向量值（λ∥及λ⊥）与肢体功能的相关关系,明确λ∥及λ⊥在神经损伤诊断中的价值。方法选取32只新西兰白兔右后肢制作兔坐骨神经牵拉伤模型,左后肢为假手术侧。于术前、术后1 d、3 d、1周、2周、3周、4周、6周、8周行双侧坐骨神经DTI扫描。测量各时间点损伤侧、假手术侧坐骨神经λ∥及λ⊥,同时观察患肢功能的变化,分析损伤后3d-8周λ⊥与患肢功能评分的相关性,后取坐骨神经各段行病理检查。结果损伤侧神经牵拉近段3dλ⊥轻度上升,2周基本恢复。牵拉段及牵拉远段1dλ⊥轻度上升,3d上升至最大值,1周后逐渐下降,4周基本恢复正常。1d-1周牵拉近段λ⊥显著高于假手术侧（F=7.275,P=0.000）。1 d-3周牵拉段及牵拉远段λ⊥显著高于假手术侧（F=5.851,F=3.794,P=0.001,P=0.000）。而λ∥损伤后神经各段与假手术侧无明显差异。牵拉段及牵拉远段λ⊥与患肢神经功能评分呈负相关（r=-0.938,-0.897,P〈0.01）。结论神经损伤后牵拉段及牵拉远段λ⊥可反映坐骨神经牵拉伤后退变与再生的客观变化,而λ∥在评价坐骨神经损伤中无明显价值。

英文摘要：

Objective To investigate the correlation between eigenvalues（λ∥ andλ⊥）of sciatic nerve and limb function in a rabbit model of acute nerve traction inj ury for finding the role ofλ∥ andλ⊥ on diagnosis of nerve inj uries.Methods The right sciatic nerves of 32 Newland rabbits were selected to be performed as traction injury,and then left sciatic nerves were treated as control for the sham operation side.MRI DTI scan was performed before and after the operation on 1 day ,3 day,and 1 week,2,3,4,6 and 8 weeks respectively.Theλ∥ andλ⊥ of inj ured sciatic nerves and sham operated nerves were measured,meanwhile functional exami-nations were evaluated,and then analyzing the correlation betweenλ⊥ of inj ured sciatic nerves and the score of inj ured limb function in the periods of 3 days to 8 weeks;finally different portions of sciatic nerve were removed for histological examinations.Results Theλ⊥ of inj ured sciatic nerves in the proximal portion was slightly increased at 3 days and recovered to the normal at 2 weeks.Theλ⊥ of inj ured sciatic nerves in the traction portion and distal portion were slightly raised at 1 day,reached to its maximum value at 3 days,and then decreased gradually after 1 week and dropped to the pre-operation level after 4 weeks.Theλ⊥ of inj ured sciatic nerves in the proximal portions was significantly higher than that of the sham-operated nerves from 1 day to 1 week（F=7.275,P=0.000）. Theλ⊥ of inj ured sciatic nerves in the traction portion and distal portion were significantly higher than that of the sham-operated nerves from 1 day to 3 weeks（F=5.851,F=3.794,P=0.001,P=0.000）.However,there was no significantly difference between theλ∥ of inj ured nerves in each portion and sham-operated nerves .The negative correlation between theλ⊥ of inj ured sciatic nerves in the distal portion and the score of the nerve function in the injured limb was found （r=-0.938,r=-0.897,P〈0.01）.Conclu-sion Theλ⊥ of inj ured nerves in the traction portion and dist