Purpose. To investigate the diagnostic performance of 18F-fluorodeoxyglucose PET/CT in patients with infective endocarditis of native valve (IENV).

Material and methods. The analysis included results of PET/CT examinations performed in 15 patients with fever of unknown origin and intraoperatively confirmed (n=13) or excluded (n=2) IENV. Patients underwent PET/CT for suspected infectious process: IENV (n=9), IE of prosthetic valve (n=3), IE of implantable intracardiac device (n=2), aortic prosthesis infection (n=1). PET/CT scan was performed 90 min after intravenous injection of 18F-FDG (175-200MBq). All patients underwent carbohydrate-free diet and fasted for at least 15-18 hours.

Results. Overall, PET/CT results correctly confirmed the infection in NV in 31%(4/13) and ruled it out in 50%(1/2) of patients. Thus, in the analyzed group (n=15), the sensitivity, specificity and diagnostic accuracy of PET/CT in IENV diagnosis were 31%, 50% and 33%, respectively; positive and negative predictive value – 80% and 10%.

In 62%(8/13) of patients with confirmed IE, whole body PET/CT revealed other than NV previously unknown foci of inflammation: in the area of aortic valve prostheses (n=2), in the lung (n=1), in the lung and along the pacemaker (n=2), along the ascending aorta prosthesis (n=1), in the lumbar vertebra (spondylodiscitis) and in the lung (n=1), in the sternum (osteomyelitis) and in the right paraclavicular soft tissue component (n=1).

Conclusion. According to initial results, 18F-FDG PET/CT showed low sensitivity in the diagnosis of IENV – negative result in the NV area does not exclude the diagnosis. PET/CT is useful in the detection of extracardiac foci of inflammation..