Freshwater drowning in a child: A case study demonstrating the role of post-mortem computed tomography

In recent years, modern imaging techniques have gained ground in forensics. A crucial question is whether virtual autopsy is capable of replacing traditional autopsy. Forensic diagnosis of freshwater drowning (FWD) is based on the evidence of findings from external inspection (e.g. frothy fluid exuding from the mouth and nostrils), internal examination (e.g. pulmonary congestion, enlargement of heart chambers) and biochemical analysis (haemodilution), findings which are non-specific. The detection of diatoms in organs of the systemic circulation may be of some assistance, but this analysis is rarely performed and is of debatable validity. An 18-month-old child was found dead at home in a swimming pool. Considering the family's wishes to avoid autopsy, the district attorney authorised a whole-body post-mortem computed tomography scan (PMCT). The main imaging findings were frothy fluid in the upper airways, fluid in the trachea and main bronchi, many pulmonary nodular ground glass opacities (GGO) in non-dependent regions and haemodilution. CT imaging did not show any other forensically relevant abnormality.A high concordance was found between the CT findings reported in the literature in cases of FWD and the imaging results. Thus, after the exclusion of other causes of death, advised by the forensic pathologist, the district attorney closed the case and the death was attributed to FWD. This case report demonstrates that PMCT imaging in cases of suspected FWD can provide some important findings for the diagnosis of FWD as the cause of death.