表观弥散系数定量评估兔肢体高压电烧伤早期肌肉进行性损伤

Apparent diffusion coefficient for quantitatively evaluating progressive muscle injury of rabbit limbs in early stage of high-voltage electrical burn

目的观察表观弥散系数(ADC)定量评价兔肢体高压电烧伤早期肌肉进行性损伤的价值。方法选取20只健康成年兔建立兔肢体高压电烧伤模型,并将其随机分为0.5、24、48及72 h组,每组5只,分别于造模后各相应时间采集右后肢MR弥散加权成像(DWI),并于其后取双侧肢体肌肉行HE染色;对比各组电流入口及出口损伤核心肌肉与正常肌肉的ADC、肌纤维密度(MFD)及肌纤维短径(D)值,分析兔损伤核心肌肉ADC值与MFD及D值的相关性。结果各组内入口及出口损伤核心肌肉与正常肌肉ADC值、入口与出口损伤核心肌肉ADC值差异均有统计学意义(P均<0.05);入口及出口核心损伤肌肉ADC值随造模时间延长而降低(P均<0.05),而正常肌肉ADC值在不同时间点差异无统计学意义(P>0.05)。入口及出口损伤核心肌肉MFD值随造模时间延长而降低(P均<0.05),而正常肌肉MFD值,以及入口、出口损伤核心和正常肌肉D值在造模不同时间点差异均无统计学意义(P均>0.05)。损伤核心肌肉ADC与MFD值正相关(r_(s)=0.846,P<0.05)、与D值呈负相关(r=-0.507,P<0.05)。结论ADC可定量评价兔肢体高压电烧伤早期肌肉进行性损伤。

Objective To observe the value of apparent diffusion coefficient(ADC)for quantitatively evaluating progressive muscle injury of rabbit limbs in early stage of high-voltage electrical burn.Methods Twenty healthy adult rabbits were selected to establish limb high-voltage electrical burn models,which were randomly divided into 0.5,24,48 and 72 h groups(each n=5).MR diffusion weighted imaging(DWI)was collected for each group at 0.5,24,48 and 72 h after modeling,and the injured core muscles of the right hind limb and the normal muscles of the contralateral limb were taken for HE staining.The muscle's ADC,muscle fiber density(MFD)and muscle fiber diameter(D)values at the injured core of current entry and exit were compared,and those of normal muscle were also analyzed.The correlations of ADC values in injured core muscle and MFD or D values were investigated.Results There were significant differences of ADC values of injured core muscle at both the entry and exit and normal muscle,also of ADC values of injured core muscle at the entry and exit within each group(all P<0.05).ADC values of injured core muscle at the entry and exit decreased with time going(all P<0.05),but ADC values of normal muscle were not significantly different among different time points(P>0.05).MFD values of injured core muscle at the entry and exit decreased with time going(all P<0.05),while MFD values of the normal muscle,D values of the injured core muscle at the entry and exit and normal muscle were not significantly different among time points(all P>0.05).ADC value of the injured core muscle was positively correlated with MFD value and negatively correlated with D value(r_(s)=0.846,r=-0.507,both P<0.05).Conclusion ADC could quantitatively evaluate the progressive muscle injury of rabbit limbs in early stage of high-voltage electrical burn.