Clinical illustration of an arterial air embolism in a patient with patent foramen ovale (PFO) can be seen in the following example in which a 57-year-old female underwent liver resection. At the end of the case, the patient became profoundly hypotensive, and an air embolism was suspected. Approximately 20 cc of air was aspirated from an indwelling central venous catheter, an Extracorporeal membrane oxygenation (ECMO) was initiated and the patient was transferred to ICU where CT brain was performed. An axial CT shows multiple areas of low attenuation representing infarction of the right (arrow) and left (arrowhead) cerebral hemispheres, consistent with underlying embolic source of infarct. Furthermore, the CT shows loss of gray-white differentiation consistent with cerebral edema. Transesophageal echocardiography was performed (not shown), revealing a large amount of air bubbles in the right and left chambers heart chambers. This, together with a patent foramen ovale, resulted in paradoxical embolism.