F-18-FDG PET/CT for early detection of embolism and metastatic infection in patients with infective endocarditis

In the acute setting of endocarditis it is very important to assess both the vegetation itself, as well as potential life-threatening complications, in order to decide whether antibiotic therapy will be sufficient or urgent surgery is indicated. A single whole-body scan investigating inflammatory changes could be very helpful to achieve a swift and efficient assessment. In this study we assessed whether F-18-FDG can be used to detect and localize peripheral embolism or distant infection. Twenty-four patients with 25 episodes of endocarditis, enrolled between March 2006 and February 2008, underwent F-18-FDG PET/CT imaging on a dedicated PET/CT scanner. PET/CT imaging revealed a focus of peripheral embolization and/or metastatic infection in 11 episodes (44%). One episode had a positive PET/CT scan result for both embolism and metastatic infection. PET/CT detected seven positive cases (28%) in which there was no clinical suspicion. Valve involvement of endocarditis was seen only in three patients (12%). PET/CT may be an important diagnostic tool for tracing peripheral embolism and metastatic infection in the acute setting of infective endocarditis, since a PET/CT scan detected a clinically occult focus in nearly one third of episodes.