Patent foramen ovale revealed by a contrast study. The injection of agitated saline fully opacified the moderately dilated right atrium and underlined a septal aneurysm bulking towards the left atrium at end-expiration (thick arrow). A large shunting through a patent foramen ovale with full opacification of the left atrium was evidenced in this patient with severe acute respiratory distress syndrome (thin arrows). Abbreviations: LA, left atrium; RA, right atrium; RV, right ventricle