18F-FDG PET/CT diagnosis of unexpected extracardiac septic embolisms in patients with suspected cardiac endocarditis

Acute infective endocarditis is a potentially life-threatening disease. Its outcome strongly depends on systemic embolization and extracardiac infections. When present, these conditions usually lead to a more aggressive therapeutic approach. However, the diagnosis of peripheral septic embolism is very challenging. F-18-Fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT has proven to be accurate for the detection of inflammatory diseases and occult infections. The aim of this study was to assess the added value of F-18-FDG PET/CT in the detection of extracardiac embolisms in the evaluation of patients with suspected valvular endocarditis (VE). Seventy-one patients with suspected infective endocarditis, enrolled between June 2010 and December 2012, underwent F-18-FDG PET/CT with the standard procedure on a dedicated PET/CT scanner. Extracardiac findings were subsequently evaluated with other imaging procedures. Of the 71 patients with suspicion of infective endocarditis, we found unexpected extracardiac findings in 17 patients (24 %) without any clinical suspicion. Extracardiac findings were subsequently evaluated with other imaging procedures. PET/CT detected unexpected extra sites of infection in 24 % of cases, leading to changes in therapeutic management in a very relevant percentage of patients. These findings may have important therapeutic implications.