Department of Diagnostic Radiology, Niigata City General Hospital, Chuo-ku, Niigata, Japan.
Forensic Sci Int. 2013 Feb 10;225(1-3):27-31. doi: 10.1016/j.forsciint.2012.04.037. Epub 2012 May 30.
The purpose of this study is to evaluate the postmortem deformation of the aorta on postmortem computed tomography (CT) by comparison with the antemortem CT in the same patient.
A total of 58 non-traumatic patients without hemorrhagic events who underwent torso CT before and shortly after death were enrolled. Antemortem chest and abdominal CT were obtained in 44 cases and in 57 cases, respectively. The lengths of the major and minor axes of the ascending and descending thoracic aorta and the abdominal aorta were measured on both antemortem and postmortem CT in the same patient. To evaluate the shape of the aorta, the major axis-minor axis ratio (Ma-MiR) was calculated. Mean values of the diameters of the aorta and Ma-MiRs on postmortem CT were compared with those on antemortem CT using the Wilcoxon signed-rank test. We also evaluated the major and minor axes and Ma-MiRs on both antemortem and postmortem CT in two age groups: 65 years and under (n=13) and over 65 years (n=45).
At each level tested, the aorta significantly shrank after death (p<0.001) (ascending thoracic aorta, descending thoracic aorta, and abdominal aorta: 38.5 mm × 33.5 mm, 28.0 mm × 25.9 mm, and 24.4 mm × 21.8 mm on antemortem CT, 30.0 mm × 26.2 mm, 24.4 mm × 20.7 mm, and 21.5 mm × 14.5 mm on postmortem CT, respectively). The postmortem Ma-MiRs significantly increased at the descending thoracic aorta and the abdominal aorta (p<0.001). The diameters of the aorta are longer in older cases at all levels on both antemortem and postmortem CT. The reduction rates were larger in younger cases than older cases at all levels.
After death, the aorta shrunk at all levels, and became oval in shape in descending thoracic and abdominal aorta. The contraction was greater in younger cases than older cases. Investigators who interpret postmortem imaging should be aware of the postmortem deformation of the aorta.
本研究旨在通过比较同一患者的死后 CT 与生前 CT，评估死后主动脉的变形情况。
共纳入 58 例无出血事件的非创伤性患者，这些患者在死亡前后均进行了胸部 CT 检查。44 例患者生前进行了胸部 CT 检查，57 例患者生前进行了腹部 CT 检查。在同一患者的生前和死后 CT 上测量升主动脉和降主动脉以及腹主动脉的长轴和短轴长度。通过计算长轴/短轴比（Ma-MiR）来评估主动脉的形状。使用 Wilcoxon 符号秩检验比较死后 CT 上主动脉直径和 Ma-MiR 的平均值与生前 CT 的相应值。我们还评估了两个年龄组（<65 岁，n=13；>65 岁，n=45）的生前和死后 CT 上的长轴、短轴和 Ma-MiR。
在每个测试水平，主动脉在死后均显著缩小（p<0.001）（升主动脉、降主动脉和腹主动脉：生前 CT 分别为 38.5mm×33.5mm、28.0mm×25.9mm 和 24.4mm×21.8mm，死后 CT 分别为 30.0mm×26.2mm、24.4mm×20.7mm 和 21.5mm×14.5mm）。死后降主动脉和腹主动脉的 Ma-MiR 显著增加（p<0.001）。在生前和死后 CT 的所有水平，老年病例的主动脉直径均较长。在所有水平，年轻病例的收缩率均大于老年病例。解释死后影像学的研究人员应了解主动脉的死后变形。
