¹⁸ F FDG PET-CT with CT Aortogram of Infected Ascending Aortic Pseudoaneurysm in a Patient with Pyrexia of Unknown Origin

Ascending aortic pseudoaneurysm is a rare but potentially fatal complication after cardiac surgery, especially when infected. We report a 68-year-old man, one-year post-coronary artery bypass graft (CABG) and triple valve replacement, who presented with persistent fever of unknown origin. Inclusion of computed tomography (CT) aortogram protocol in routinely performed whole body 18 F fluorodeoxyglucose (FDG) positron emission tomography/ computed tomography (PET/CT) identified a pseudoaneurysm originating from the anterior ascending aortic wall with contrast opacification and a surrounding FDG-avid periaortic collection, favouring active infection. This case highlights the diagnostic value of whole-body PET/CT with CT aortogram in detecting infected ascending aortic pseudoaneurysm in complex postoperative patients with pyrexia of unknown origin.