Can post-mortem CT reliably distinguish between drowning and non-drowning asphyxiation?

The aim of this study is to evaluate whether previously reported post-mortem CT findings in drowning can reliably distinguish drowning from asphyxiation by any other manner. Cases (n = 14) were corpses with cause of death determined as drowning by concordant autopsy findings and physical and circumstantial evidence. Controls (n = 11) were corpses in which the cause of death was defined as asphyxiation by any other manner than submersion in a liquid. Images were evaluated for the presence of fluid in paranasal sinuses, mastoid air cells and lower airways, frothy foam in the upper airways, ground-glass opacity of the lung parenchyma, the height of the right hemi-diaphragm, the interpulmonary distance at the level of the aortic valve, the mean density of intracardiac blood, and gastric and esophageal contents. Descriptive statistics, Fisher's exact test, and Student's t test were used when appropriate. Only the height of the right hemi-diaphragm differed significantly (p = 0.045) between cases (mean 5.4) and controls (mean 4.3). Other findings were not significantly different between both groups. Our results indicate that it is not possible to reliably distinguish drowning from non-drowning asphyxiation on CT, because many findings in drowning were also present in non-drowning asphyxiation. CT indicators for drowning as the cause of death should therefore be defined with great caution, keeping in mind that they are not specific to only a single cause of death.