多体素^1H—MRS推断不同温度下死亡时间的研究  

The study on estimation of time since death with multivoxel-voxel proton ^1H-MR spectroscopy at different temperatures

作　　者：杨天潼[1,2] 李振伟[3] 刘良[1,2] 郑娜[1] 

机构地区：[1]华中科技大学同济医学院法医学系,湖北武汉430030 [2]中国政法大学证据科学教育部重点实验室,北京100040 [3]华中科技大学同济医学院附属同济医院放射科,湖北武汉430030

出　　处：《中国法医学杂志》2008年第6期379-382,共4页Chinese Journal of Forensic Medicine

摘　　要：目的利用多体素质子磁共振波谱（^1H-MRS）技术推断不同温度下的死亡时间。方法选取24只白兔，分为两组，利用多体素质子磁共振波谱测定死后30min、1h、2h、4h、6h、8h、12h、16h、24h脑内N-乙酰天门冬氨酸、胆碱复合物、磷酸肌酸和肌酸各代谢物之间峰下面积的比值。结果死后24h内N-乙酰天门冬氨酸与磷酸肌酸和肌酸的比值随死亡时间的延长而降低，胆碱复合物与磷酸肌酸和肌酸的比值随死亡时间的延长而升高。Naa／Cr、Ch／Cr与PMI进行回归分析：自变量为Naa／Cr的二次多项式方程为：Y=0．0020x^2-0．0815x＋1．4532（R^2=0．971）；自变量为Ch／Cr的二次多项式方程为：Y=-0．0024x^2＋0．0870x＋1．1876（R^2=0．962）。用Naa／Cr的方程推测PMI，当PMI〈24h时，平均偏离时间为1．70～50．27min，用Ch／Cr的方程推测PMI，当PMI〈24h时，平均偏离时间为1．12～98．11min。结论Naa／Cr、Ch／Cr的死后变化与时间呈强相关性，可用于死亡时间推断。Objective To investigate a method for estimation of time since death with multivoxes-voxel proton ^1H-MR spectroscopy at different tmperatures. Methods Metabolite peak area ratios of Naeetylaspartate （Naa） or choline （ch） to creatine （Cr） were dtermined by ^1H-MR spectroscopy （1H-MRS） in the brain in 24 rabbits 30min,1h, 2h, 4h, 6h, 8h, 12h, 16h and 24h after death respectively. Results Naa/Cr ratia was decreased, while Ch/Cr increased with the extension of postmortem interval within 24 hours. Having Naa/Cr as the independent variable, the quadratic polynomial regression equation was expressed as y = - 0. 0024x^2 ＋ 0. 0870x ＋ 1. 1876 （ R^2 = 0. 962, Equation 1 ） ; having Ch/Cr as the independent variable,the quadratic polynomial regression equation was expressed as y = - 0.0024x^2 ＋ 0. 0870x ＋ 1. 1876 （ R^2 =0. 962, Equation 2）. When PMI was estimated by Equation 1, the average deviation was approxiamtely 1.70 -50.27min, and when by Equation 2, the average deviations was approxiamtely 1.12 -98.11 min. Conclusion There is a definite relationship between Naa/Cr, or Ch/Cr and PMI, which may be used for estimation of time since death.

关 键 词：法医病理学 死亡时间 多体素氢质子 磁共振波谱 

分 类 号：D919[医药卫生—法医学]