Drowning is one of the most prevalent causes of non-natural death with typical postmortem imaging findings. According to the World Health Organisation (WHO), an estimated 360,000 annual deaths occur due to drowning.
This article concerns itself with postmortem appearances in fatalities from drowning. For non-fatal pulmonary changes please refer to near-drowning pulmonary oedema.
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Pathology
Drowning describes the process of submersion of at least the face in a liquid medium, followed by respiratory impairment and aspiration of fluids into the respiratory tract. Drowning is, therefore, a form of asphyxia. While aspiration of fluid into the lungs, known as "wet drowning", is most common, "dry drowning" without fluid aspiration occurs in about 10-15% of cases.
Radiographic features
CT
Drowning presents with a number of typical but not highly specific findings 2:
- frothy foam in the nasal cavity and pharynx
- fluid in the paranasal sinuses
- found most often in the maxillary and ethmoidal sinuses followed by the sphenoidal and frontal sinuses 3
- density measurements can differentiate saltwater and freshwater contents: saltwater has a higher density (mean 47 HU) than freshwater (32 HU) 5
- fluid in the mastoid cells
- fluid in the trachea and main bronchi
-
ground-glass opacity (GGO) in the lungs forming a mosaic pattern, which may be differentiated as 1
- reticular GGO with interstitial thickening
- patchy GGO along the airways
- (bilateral) pleural effusions 3,4
- fluid distension and increased volume of the stomach and small intestine
- the volume of the stomach has a water-like density and is often layered in solid, liquid, and foam; see Wydler sign (forensic)
- increased total lung volume and decreased radiodensity (HU) and lung density (g/L 6