BackgroundThis study aimed to assess the impact of dedicated cardiac protocol (DCP) on diagnostic accuracy of state-of-the-art digital [18F]-FDG-PET/CT in infective endocarditis (IE) and the intra-individual comparison of the performance with that of conventional whole-body approach (WBA) and to analyze the effects of expertise level of the investigators. Methods44 patients suspected for IE underwent digital-FDG-PET/CT after overnight fasting. Each three consultants and trainees reread PET-images blinded to examination approach and clinical information. Visual and semiquantitative analyses were performed. ResultsDigital-FDG-PET/CT with DCP revealed sensitivity, specificity and accuracy of 89%, 93% and 91% for native valve endocarditis (NVE) and 93%, 86% and 91% for prosthetic valve endocarditis. Compared to WBA, substantial improvement of the diagnostic performance for NVE in DCP was evident, especially in trainees, but not as high compared to consultants. Digital-FDG-PET/CT enabled 79.5% reclassification of modified-Duke-Clinical-Criteria (mDC) with 34.1% upgrading and 45.4% downgrading. ConclusionThis study provides new data using state-of-the-art digital-FDG-PET/CT with DCP improving the diagnostic accuracy in challenging cases of possible IE, particularly in NVE, provided that the investigators involved have the necessary expertise. These findings may have a significant impact on IE-related morbidity, mortality and patient’s management and might be meaningful for updates of the prevailing opinion regarding the value of FDG PET/CT in NVE.