Ludwig Boltzmann Institute for Clinical-Forensic Imaging, Graz, Austria.
AJNR Am J Neuroradiol. 2011 Sep;32(8):1518-24. doi: 10.3174/ajnr.A2508. Epub 2011 Jun 9.
DWI and DTI of the brain have proved to be useful in many neurologic disorders and in traumatic brain injury. This prospective study aimed at the evaluation of the influence of the PMI and the cause of death on the ADC and FA for the application of DWI and DTI in forensic radiology.
DWI and DTI of the brain were performed in situ in 20 deceased subjects with mapping of the ADC and FA. Evaluation was performed in different ROIs, and the influence of PMI and cause of death was assessed.
Postmortem ADC values of the brain were decreased by 49%-72% compared with healthy living controls. With increasing PMI, ADCs were significantly reduced when considering all ROIs together and, particularly, GM regions (all regions, P < .05; GM, P < .01), whereas there was no significant effect in WM. Concerning the cause of death, ADCs were significantly lower in mechanical and hypoxic brain injury than in brains from subjects having died from heart failure (traumatic brain injury, P < .005; hypoxia, P < .001). Postmortem FA was not significantly different from FA in living persons and showed no significant influence of PMI or cause of death.
Performing postmortem DWI and DTI of the brain in situ can provide valuable information for application in forensic medicine. ADC could be used as an indicator of PMI and could help in the assessment of the cause of death.
弥散加权成像（DWI）和弥散张量成像（DTI）已被证明在许多神经疾病和外伤性脑损伤中具有重要作用。本前瞻性研究旨在评估死后时间（PMI）和死因对 ADC 和 FA 的影响，以便将 DWI 和 DTI 应用于法医放射学。
对 20 例死亡患者的脑进行了 DWI 和 DTI 检测，并对 ADC 和 FA 进行了映射。在不同的 ROI 中进行了评估，并评估了 PMI 和死因的影响。
与健康活体对照相比，死后大脑的 ADC 值降低了 49%至 72%。随着 PMI 的增加，当考虑所有 ROI 时，ADC 显著降低，尤其是 GM 区域（所有区域，P <.05；GM，P <.01），而 WM 区域则无显著影响。就死因而言，机械性和缺氧性脑损伤的 ADC 值明显低于心力衰竭死亡患者（外伤性脑损伤，P <.005；缺氧，P <.001）。死后 FA 与活体人员的 FA 无显著差异，且不受 PMI 或死因的显著影响。
对尸体进行脑 DWI 和 DTI 原位检测可提供有价值的信息，用于法医应用。ADC 可作为 PMI 的指标，并有助于死因评估。
