Forensic pathological evaluation of postmortem pulmonary CT high-density areas in serial autopsy cases of sudden cardiac death

Previous studies suggested substantial postmortem interference with pulmonary CT findings. The present study evaluated postmortem CT (PM-CT) morphology of the lung, compared with histology, in autopsy cases of sudden cardiac death without recovery from cardiac arrest (SCD, n = 22) with regard to the posture at the time of death and postmortem interference from a forensic pathological viewpoint. In witnessed cases (n = 5), a case of SCD in a prone position had anterior consolidation with weak hypostatic opacification in the posterior about 18 h later. Among unwitnessed deaths (n = 17), 8 cases of death lying prone, sitting facedown and lying laterally had possible gravity-dependent opacity about 15-38 h postmortem. Hypostatic opacification with 'niveau' formation was not evident in more than half of the cases (n = 15). Histological findings for ground glass opacification and consolidation on PM-CT varied by case, involving intraalveolar edema and hemorrhages, accompanied by marked congestion; however, possible postmortem hypostatic opacification mostly represented intraalveolar edema. CT morphology of acute pulmonary congestion in SCD may often remain without serious postmortem interference in cases without clinical intervention involving massive fluid infusion, suggesting plain PM-CT findings of the lung to be useful for investigating the death process when combined with histology; however, the possible influence of the hydration status of the lungs at the time of death should be assessed by evaluation of CT and autopsy findings.