【摘要】 目的探讨磁共振弥散张量成像(DTI)在评价兔失神经靶肌肉退变及再生的价值。方法将36只新西兰大白兔右后肢制作失神经支配骨骼肌退变及再生模型,分别于术前、术后1d、3d、1周、2周、3周、4周、6周、8周各时间点对靶肌肉进行DTI及病理检查,每时间点4只,观察失神经侧与对侧正常组腓肠肌及比目鱼肌的FA、ADC值,λ∥,λ⊥值及病理学变化特点。结果 36只兔全部造模成功,术后第1天,失神经侧靶肌肉λ∥值、λ⊥值及FA值均开始下降,以λ∥值最显著,与术前比较有统计学差异(P<0.05),病理上靶肌肉肌纤维间质出现水肿;3d～4周,λ∥值、λ⊥值及FA值均逐渐下降,2周时FA值下降至最低值,而λ∥值、λ⊥值分别在4周时下降至最低值,而病理上有血管扩张、充血淤血、渗出、肌纤维灶性萎缩、肌肉间隙增宽的出现;6～8周,三者均逐渐升高、缓慢恢复,相对应病理改变逐渐减轻。经LSD法进行组间对比:λ∥值、λ⊥值及FA值与正常组有统计学差异的分别为1d～6周,1～6周及1～6周(P<0.05),而ADC在各组观察期与损伤前均无明显变化。结论失神经靶肌肉的弥散参数λ∥值、λ⊥值及FA值与其病理变化的趋势相一致,DTI能早期、敏感、准确评价失神经靶肌肉退变及再生的情况。更多还原

【Abstract】 Objective To investigate the diffusion tensor imaging(DTI) used for evaluation of the denervation and reinnervation in rabbit muscles. Methods Denervation and reinnervation models were constructed at the tracting sciatic nerve of the right posterior limb in 36 healthy New-Zealand rabbits. Magnetic resonance diffusion tensor imaging (MRDTI) and histologic observation of the target muscle were carried out preoperatively, and at 1st day, 3rd day, 1 week, 2 weeks, 3 weeks, 4 weeks, 6 weeks, and 8 weeks after surgery (n=4, at each time point). FA, ADC, λ∥ and λ⊥ values in denervation muscle and the normal muscle were determined, and the pathological features were observed. Results Animal models were sucessfully established in all 36 rabbits. λ∥, λ⊥ and FA decreased when the interstitial edema was observed in target muscle fibers on the first day after the surgery. λ∥ decreased markedly and there was significant difference compared with preoperative values (P<0.05). λ∥, λ⊥ and FA decreased gradually and fell to the lowest value respectively in 2 and 4 weeks; vasodilation, congestion, exudation, focal atrophy of muscle fibers and widened muscle gaps were observed by histological study in the following 3 day to 4 weeks. In the following 6-8 weeks, the values of the three parameters increased gradually, with pathological changes were gradually lessened. The LSD method showed that compared with the normal group, λ∥ values, λ⊥ values and FA values were significant different at one day to 6 weeks, and 1 week to 6 weeks respectively. Conclusions Diffusion parameters (λ∥, λ⊥ and FA) of denervation and reinnervation have consistent trend with the pathological changes. DTI can provide early, sensitive, and accurate elaluation of denervation and reinnervation.更多还原