Okuma Hidemi, Gonoi Wataru, Ishida Masanori, Shirota Go, Kanno Shigeaki, Shintani Yukako, Abe Hiroyuki, Fukayama Masashi, Ohtomo Kuni
Department of Radiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
Department of Radiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
Leg Med (Tokyo). 2017 Jan;24:86-91. doi: 10.1016/j.legalmed.2016.12.006. Epub 2016 Dec 21.
As postmortem imaging has gained prominence as a supplement to traditional autopsy, it is important to understand the normal postmortem changes to enable the accurate evaluation of postmortem imaging. No studies have evaluated the postmortem changes in cardiothoracic ratio (CTR) compared with antemortem images in the same subjects. We studied 147 consecutive subjects who underwent antemortem and postmortem CT, and autopsy. Postmortem CT was performed <23h after death and was followed by autopsy. The subjects were divided into three groups: normal heart, old myocardial infarction, and CPR-treated hearts. CTR was compared between antemortem and postmortem CT using paired t tests, which revealed that the CTR was greater on postmortem CT than on antemortem CT in all groups (mean CTR: 0.53±0.06vs. 0.50±0.06, respectively; P<0.01). Sex, age, time elapsed since death, and the causes of death were examined as potential confounding factors for the postmortem changes in CTR, but no significant associations were found. Receiver-operating characteristic (ROC) curves were used to determine CTR values for cardiomegaly, which was defined according to the autopsy weight of the heart. The area under the ROC curve was 0.71 (95% confidence interval 0.63-0.79). The CTR threshold of 0.54 identified cardiomegaly with the greatest accuracy, compared with the general threshold of 0.50. In conclusion, the CT-determined CTR increases after death, irrespective of the heart's condition. We should be cautious of overdiagnosis of cardiomegaly on postmortem CT, and new criteria for interpreting cardiomegaly on postmortem CTR are needed.
随着尸体解剖成像作为传统尸检的补充手段而日益受到重视，了解正常的死后变化对于准确评估尸体解剖成像至关重要。尚无研究将同一受试者的死后心胸比率（CTR）变化与生前图像进行比较。我们对147例连续接受生前和死后CT检查及尸检的受试者进行了研究。死后CT在死亡后<23小时进行，随后进行尸检。受试者分为三组：正常心脏组、陈旧性心肌梗死组和心肺复苏治疗组。使用配对t检验比较生前和死后CT的CTR，结果显示所有组的死后CT的CTR均高于生前CT（平均CTR：分别为0.53±0.06和0.50±0.06；P<0.01）。对性别、年龄、死亡时间和死因作为CTR死后变化的潜在混杂因素进行了检查，但未发现显著关联。使用受试者操作特征（ROC）曲线确定心脏肥大的CTR值，心脏肥大根据心脏尸检重量定义。ROC曲线下面积为0.71（95%置信区间0.63-0.79）。与一般阈值0.50相比，CTR阈值为0.54时对心脏肥大的识别准确性最高。总之，无论心脏状况如何，CT测定的CTR在死后都会增加。我们应警惕在死后CT上对心脏肥大的过度诊断，并且需要新的标准来解释死后CTR上的心脏肥大。
