家兔失血性休克死后肝脏CT影像学变化与死亡时间的关系

Experimental Study on Estimating the Postmortem Interval in Rabbits Hemorrhagic Shock Death Model Using Liver Computed Tomography Images

目的研究家兔失血性休克死后129 h内肝脏CT影像学的变化与死后经过时间的关系。方法以失血性休克处死家兔,在死后不同时间对家兔进行肝脏螺旋CT扫描,选取第一腰椎层面测定肝组织平均CT值和肝脏面积/腰椎面积。结果肝脏面积/腰椎面积在肝窗上呈现"相对不变—快速减小—缓慢减小"的时间变化,肝脏组织平均CT值呈先上升后下降的总体趋势。将每个参数的测量值进行多项式运算,获得了更能体现2项指标与死亡时间关系的二项式回归方程,均具有高度的统计学意义(P均<0.01)。结论 CT扫描可动态、客观显示家兔死后肝脏的影像学变化,肝脏组织平均CT值变化对早期死亡时间推断更准确,肝脏面积/腰椎面积变化对中晚期死亡时间推断更灵敏。

Objective To investigate the relationship between changes in the liver computed tomography（CT） images and the postmortem interval（PMI） of rabbits 129 h after their death due to hemorrhagic shock. Methods CT scanning was used to investigate the hemorrhagic shock death model in 23 rabbits to identify the postmortem cerebral changes from 0 h to 129 h after death. Results The liver or lumbar area in the liver window showed the following characteristic changes：from unchanged,to rapid shrinkage,to slow shrinkage;the mean CT values of the liver initially increased and subsequently decreased. The regression equations for the relationship between the two indices and PMI were established by surgery,and they all had statistical significance（P 0.01）. Conclusion CT scanning can accurately show changes in the rabbit liver after death. The mean CT value of the liver tissue is more sensitive for inferring early PMI. Furthermore,the liver area/lumbar area ratio parameters are more sensitive for inferring mid-late PMI.