[不同温度下利用单体素质子1H-磁共振波谱法估计死亡时间]

[Estimation of postmortem interval with single-voxel proton 1H-MR spectroscopy at different temperature].

作者信息

Yang Tian-Tong, Li Zhen-Wei, Liu Liang, Zhen Na

机构信息

Department of Forensic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.

出版信息

Fa Yi Xue Za Zhi. 2008 Apr;24(2):85-9.

PMID:18605034

Abstract

OBJECTIVE

To find an objective method for estimation of postmortem interval (PMI) with single-voxel proton MR spectroscopy at different temperature.

METHODS

Changes of metabolite peak area and peak area ratio of the N-acetylaspartate (Naa), choline (Cho) and total creatine (Cr) in the brain of 24 rabbit models were measured by 1H-MR spectroscopy (1H-MRS) at 0.5, 1, 2, 4, 6, 8, 12, 16 and 24 h, respectively after death.

RESULTS

Naa and Cr decreased continuously with the extension of PMI, and the ratios of Naa/Cr and Cho/Cr also decreased continuously with the extension of PMI within 24 h. The quadratic polynomial regression equation is y=0.0019x2-0.803x+1.4498 (R2=0.962) (Equation 1) with the Naa/Cr used as an independent variable, while the quadratic polynomial regression equation is y=-0.0024x2+0.926x+1.1777 (R2=0.986) (Equation 2) with the Cho/Cr used as an independent variable. The average deviations were about 2.10-37.90 min and 1.69-40.87 min, respectively if the PMI was estimated by Equation 1 and Equation 2, respectively.

CONCLUSION

Our study indicates that there is a strong correlation between Naa/Cr, Cho/Cr and PMI, which may be used for estimation of PMI at different temperature.

摘要

目的

寻找一种在不同温度下通过单体素质子磁共振波谱法估计死亡时间（PMI）的客观方法。

方法

对24只兔模型在死后分别于0.5、1、2、4、6、8、12、16和24小时，通过氢质子磁共振波谱法（1H-MRS）测量大脑中N-乙酰天门冬氨酸（Naa）、胆碱（Cho）和总肌酸（Cr）的代谢物峰面积及峰面积比的变化。

结果

随着PMI延长，Naa和Cr持续下降，在24小时内Naa/Cr和Cho/Cr比值也随PMI延长而持续下降。以Naa/Cr为自变量的二次多项式回归方程为y = 0.0019x² - 0.803x + 1.4498（R² = 0.962）（方程1），以Cho/Cr为自变量的二次多项式回归方程为y = -0.0024x² + 0.926x + 1.1777（R² = 0.986）（方程2）。若分别用方程1和方程2估计PMI，平均偏差分别约为2.10 - 37.90分钟和1.69 - 40.87分钟。