18F-FDG PET/CT Detection of a Popliteal Mycotic Aneurysm Complicating Staphylococcus aureus Bacteremia.

A 75-year-old man presented with Staphylococcus aureus bacteremia, fever, and right posterior knee pain. Venous Doppler ultrasound of the lower extremity showed an isolated right calf muscle vein thrombosis, without any sign of deep vein thrombosis. 18F-FDG PET/CT revealed an intense focal uptake on the right popliteal artery, suggesting a mycotic aneurysm (MA). Lower limb CT angiography confirmed an MA of the right popliteal artery. The patient underwent surgical procedure with excision of the MA, whose cultures grew methicillin-sensitive S. aureus. Our case highlights the importance of including lower limbs in 18F-FDG PET/CT acquisition in case of suspicion of septic emboli.