Classification of hemopericardium on postmortem CT.

Postmortem CT (PMCT) is increasingly used in forensic practice, and knowledge and classification of typical hemopericardium on PMCT would help to assure correct radiological interpretation. The goal of this study was to evaluate the pericardial and pleural space fluid volumetry, and to evaluate the signs on PMCT pointing to cardiac tamponade as the cause of death, and their pitfalls. Fourteen cadavers (eleven male, three female, 49-87 [mean, 70.9] years) were examined by PMCT. The pericardial volume and pericardial findings with/without pleural space fluid collection were compared with autopsy findings. In addition, the appearance of pericardial lesions on PMCT was documented and compared with the autopsy findings. The respective volumes of pericardial space, and right and left pleural space fluid showed as 172.0-711.0 (mean 368.7) ml, 0-1830.0 (266.1) ml, 0-231.0 (75.2) ml on PMCT, and were 136.0-652.0 (311.1) ml, 0-2100 (299.0) ml, and 0-300.0 (61.3) ml on autopsy. In statistical evaluation, the pericardial space volume was significantly greater on PMCT (p<0.05), but there was no significant difference in pleural space fluid volume. The hemopericardium PMCT showed 3 patterns: double band, single band, and horizontal level, and the former two patterns presented as coagulated blood at autopsy. Single band and horizontal level patterns were thought to result from CPR-related causes and/or postmortem manipulation. In conclusion, double and single band patterns on PMCT were indicative findings of cardiac tamponade. An understanding of the pericardial PMCT appearance and its significance can help to avoid misreading, and is important for making correct radiological interpretation.