Sogawa Nozomi, Michiue Tomomi, Ishikawa Takaki, Kawamoto Osamu, Oritani Shigeki, Maeda Hitoshi
Department of Legal Medicine, Osaka City University Medical School, Asahi-machi 1-4-3, Abeno, Osaka 545-8585, Japan; Forensic Autopsy Section, Medico-legal Consultation and Postmortem Investigation Support Center (MLCPI-SC), c/o Osaka City University Medical School, Asahi-machi 1-4-3, Abeno, Osaka 545-8585, Japan.
Department of Legal Medicine, Osaka City University Medical School, Asahi-machi 1-4-3, Abeno, Osaka 545-8585, Japan; Forensic Autopsy Section, Medico-legal Consultation and Postmortem Investigation Support Center (MLCPI-SC), c/o Osaka City University Medical School, Asahi-machi 1-4-3, Abeno, Osaka 545-8585, Japan.
Forensic Sci Int. 2014 Aug;241:112-7. doi: 10.1016/j.forsciint.2014.05.012. Epub 2014 May 24.
Postmortem CT (PMCT) is useful to investigate air/gas distribution and content in body cavities and viscera. The present study investigated the procedure to estimate total lung air/gas content and aeration ratio as possible indices of terminal respiratory function, using three-dimensional (3-D) PMCT data analysis of forensic autopsy cases without putrefactive gas formation (within 3 days postmortem, n=75), and analyzed the volumetric data with regard to the cause of death. When 3-D bilateral lung images were reconstructed using an image analyzer, combined lung volume was larger in drowning (n=12) than in alcohol/sedative-hypnotic intoxication (n=8) and sudden cardiac death (SCD; n=10), and intermediate in other cases, including mechanical asphyxiation (n=12), fire fatalities due to burns (n=6) and carbon monoxide intoxication (n=7), fatal methamphetamine abuse (n=7), hyperthermia (heatstroke; n=6) and fatal hypothermia (cold exposure; n=7). Air/gas content of the lung as detected using HU interval between -2000 and -400 ('effective' lung aeration areas) and between -2000 and -191 (total lung aeration areas) as well as the ratios to total lung volume ('effective' and total lung aeration ratios, respectively) was higher in mechanical asphyxiation, drowning, fatal burns and hypothermia (cold exposure) than in SCD, and was intermediate in other cases. 'Effective' and total lung aeration ratios may be useful for comparisons between specific causes of death to discriminate between hypothermia (cold exposure) and drug intoxication, and between SCD and other causes of death, respectively. These findings provide interesting insights into potential efficacy of PMCT data analyses of lung volume and CT density as well as lung air/gas content and aeration ratio with regard to the cause of death, as possible indicators of terminal respiratory function, as part of virtual autopsy of the viscera in situ.
尸检CT（PMCT）有助于研究体腔和内脏中的空气/气体分布及含量。本研究采用三维（3-D）PMCT数据分析无腐败气体形成（死后3天内，n = 75）的法医尸检案例，探讨估算肺总空气/气体含量及通气率作为终末呼吸功能可能指标的方法，并分析了死因的容积数据。使用图像分析仪重建3-D双侧肺图像时，溺水（n = 12）患者的双肺合并体积大于酒精/镇静催眠药中毒（n = 8）和心源性猝死（SCD；n = 10）患者，在其他病例中居中，包括机械性窒息（n = 12）、烧伤致死（n = 6）、一氧化碳中毒（n = 7）、甲基苯丙胺滥用致死（n = 7）、体温过高（中暑；n = 6）和低温致死（寒冷暴露；n = 7）。使用-2000至-400 HU区间（“有效”肺通气区域）和-2000至-191 HU区间（肺总通气区域）检测的肺空气/气体含量以及与肺总体积的比值（分别为“有效”和肺总通气率）在机械性窒息、溺水、烧伤致死和低温（寒冷暴露）时高于SCD，在其他病例中居中。“有效”和肺总通气率可能分别有助于比较特定死因，以区分低温（寒冷暴露）和药物中毒，以及SCD和其他死因。这些发现为将PMCT对肺体积、CT密度以及肺空气/气体含量和通气率的数据分析作为终末呼吸功能的可能指标、作为原位内脏虚拟尸检的一部分用于推断死因提供了有趣的见解。
