【摘要】 目的探讨兔急性失神经骨骼肌再生修复的T2值-时间曲线变化与病理学的关系。方法 44只新西兰兔挤压右侧坐骨神经建立腓肠肌再生模型,于不同时间段行MRI扫描,后行病理学检查。结果失神经腓肠肌48hT2值开始升高[T2=(32·49±0·98)ms],5周达高峰[T2=(50·62±1·75)ms],6周开始降低[T2=(45·41±1·39)ms],10周T2值大部分恢复正常[T2=(31·73±0·73)ms]。T2值48h至9周均高于假手术侧(F=13·00～694·12,P<0·05)。光镜下,失神经腓肠肌24h细胞间质轻度水肿,48h局部毛细血管扩张、炎性细胞浸润;1～5周主要表现为局部毛细血管持续扩张、间质水肿、炎症细胞浸润、肌肉变性。6～7周毛细血管较前缩小,间质水肿减轻。8～10周毛细血管逐渐恢复正常大小,肌纤维横截面积较前增大。T2值升高主要由于失神经肌肉间质水肿、局部毛细血管扩张;T2值降低与血管恢复正常、间质水肿减轻、肌纤维修复相一致。结论 T2值动态测量可反映失神经骨骼肌再生修复的病理变化,MRI可作为评价失神经骨骼肌再生的敏感、可靠方法。更多还原

【Abstract】 Objective To prospectively evaluate magnetic resonance(MR) signal abnormalities and the time course of T2 values in rabbit models of denervated muscle with histology.Methods Acute denervated muscle models were set up by crushing the right sciatic nerves 44 rabbits.The contralateral sham-operated sides served as controls.Sequential MR imaging and T2 measurements were obtained over a 70-day follow-up period,with histologic assessments performed at regular intervals.Results The denervated gastrocnemius muscle showed slight hyperintense signals on T2 maps as early as 48 hours,and the T2 value at 48 hour was(32.49±0.98)ms,which further increased during one to four weeks,and reached a maximum at five weeks(50.62±1.75)ms.Subsequently,the T2 values began to decrease at six weeks(45.41±1.39)ms,then normalized at 10 weeks.T2 values were in a higher level from 48h to 9 weeks postoperation on model sides than on sham-operated sides(F=13.00~694.12,P<0.05).Based on microscopy,extracellular water volume increased in 24 hours after surgery.Inflammatory reaction and an enlargement of the muscle capillaries developed at 48 hours.Significant muscle fiber atrophy could be detected at seven days after the trauma,with a decrease of the mean fiber area.After six weeks or seven weeks,the capillary size and extracellular fluid decreased and muscle fiber atrophy resolved.The pattern of a rapid rise followed by gradual recovery in T2 values was well correlated with the functional recovery pattern.ConclusionsThe changes of T2 values is an early sign of muscle denervation and regeneration,which markedly precedes muscle atrophy and regeneration.Dynamic T2 value measurement of denervated muscles is a sensitive and reliable method to monitor the change of denevated muscles.更多还原