Infective endocarditis detected by 18F-fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography in a patient with occult infection

Integrated 18F-fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography (FDG PET/CT) has been clinically used to detect infectious lesions. We present a case with pyrexia and bacteremia of unknown origin. Whole body FDG PET/CT was arranged to look for an occult source of infection and it revealed a focal lesion with increased FDG uptake in the mitral valve area. Under suspicion of infective endocarditis, transthoracic echocardiography was repeated and then the presence of linear vegetation over the calcified mitral annulus was confirmed. Ultimately, definite infective endocarditis was diagnosed according to the Duke criteria. The patient recovered after the antibiotic therapy. In our case, FDG PET/CT can help to localize the exact site of occult infection, thereby guiding additional testing and facilitating timely definitive diagnosis and therapy.