Role of Molecular Imaging in the Diagnosis of Prosthetic Aortic Valve Endocarditis by Bacillus Licheniformis: A Case Report

Abstract Background Infective endocarditis is a challenging diagnosis that usually requires cardiovascular image confirmation as part of the approach. 18F-FDG PET/CT an imaging technique more sensible for prosthetic valve when echocardiography inconclusive. Case Summary We present case 35-year-old man who had previous Bentall-De Bono procedure four years prior included biological, INC-type, locally manufactured aortic replacement and woven Dacron tube graft implantation in ascending aorta. He was admitted because dyspnea, edema, fever, syncope. A complete auriculoventricular blockade diagnosed, requiring cardiac pacing. Also, infective (IE) suspected. Blood cultures showed isolation Bacillus licheniformis. Transthoracic (TTE), transesophageal (TEE), computed tomography angiography (CTA) were inconclusive IE. Treatment initiated with IV antibiotic therapy, extensive protocol IE, including molecular modalities, ordered. 99mTc-Ubiquicidine scintigraphy acquired without abnormal findings. Images 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (18F-FDG- PET) revealed abnormally intense heterogeneous uptake annulus classic pattern. Applying modified 2015 Duke Criteria PET/CT, (PVE) confirmed. Discussion Although other modalities negative, high clinical suspicion made it mandatory to continue study protocol, remarking on utility patients categorized having ¨possible¨ endocarditis, our patient.