FIT CDM Sample Case
Use of 18F-Fluorodeoxyglucose (FDG) Positron Emission Tomography/Computed Tomography (PET/CT) for Diagnosing Prosthetic Valve Perivalvular Abscess
Background: Prosthetic valve infective endocarditis (PVE) remains a diagnostic challenge and is associated with high morbidity and mortality.
Case: A 52-year-old man presented with four days of fever and chills. His medical history included congenital bicuspid aortic valve stenosis and endocarditis with mechanical aortic valve replacement at age 40. Physical exam demonstrated Janeway lesions. An electrocardiogram (ECG) revealed first-degree atrioventricular (AV) block. Transthoracic and transesophageal echocardiogram did not reveal PVE (Figure 1A-C). Initial broad-spectrum antibiotics were changed to oxacillin, rifampin, and gentamicin for methicillin-sensitive staphylococcus aureus bacteremia. Subsequent blood cultures were negative. He developed anuric renal failure requiring hemodialysis. Brain MRI revealed septic emboli. Daily ECGs were notable for an evolving first-degree AV block.
Decision-making: Due to high re-operative risk, optimal timing of surgery was challenging. A perivalvular abscess would be an indication for urgent surgical operation. A decision was made to perform cardiac 18F-FDG PET/CT (Figure1D-G), which confirmed PVE. Urgent surgical intervention revealed a large abscess at the right and left coronary cusps that was debrided, and a 21mm Reagent mechanical valve was successfully implanted (Figure 1H).
Conclusion: This case highlights the challenge in diagnosis of PVE and the successful use of 18F-FDG PET/CT for the management of PVE. Click here to see the full case presentation.
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