Postmortem virtual volumetry of the heart and lung in situ using CT data for investigating terminal cardiopulmonary pathophysiology in forensic autopsy

Abstract

Postmortem CT (PM-CT) is useful to investigate the viscera in situ before opening the body cavity at autopsy. The present study investigated heart and lung volumes in situ with regard to the cause of death as possible indexes of terminal cardiopulmonary dysfunction by means of PM-CT data analysis of forensic autopsy cases within 3 days postmortem (n=70). Estimated heart volume was larger in sudden cardiac death (SCD; n=10) and fatal methamphetamine abuse (n=5) than in other groups, including mechanical asphyxiation (n=12), drowning (n=11), acute alcohol/sedative-hypnotic intoxication (n=8), fire fatality (n=12), hyperthermia (heatstroke; n=6) and fatal hypothermia (cold exposure; n=6). Estimated combined lung volume was larger in drowning, smaller in fire fatality due to carbon monoxide intoxication and SCD, and intermediate in other groups. Volume ratio of the lung to heart was higher in drowning, lower in SCD, and intermediate or varied in other groups; high and low ratios can indicate predominant/antecedent pulmonary and cardiac dysfunctions, respectively. These findings provide quantitative data that are not available at conventional autopsy or by routine two-dimensional CT morphology to assess three-dimensional gross heart and lung morphologies for interpreting terminal cardiopulmonary pathophysiology, detecting significant difference between SCD and other causes of death, especially mechanical asphyxiation and drowning.

Keywords: Cardiorespiratory function; Forensic radiology; Heart; Lung; Mode of death; Postmortem CT.