figure a

A 69-year-old woman with a history of rheumatic valvulopathy requiring mechanical prosthetic valve substitution 11 years previously was admitted to our service because of fever. Physical exploration was unremarkable. Blood cultures were positive for cloxacillin-resistant Staphylococcus epidermidis. The echocardiogram showed a large mitral vegetation without signs of perivalvular abscess or prosthetic dysfunction. The patient received a 6-week regimen of daptomicin, gentamicin and rifampicin, with immediate negativization of the blood cultures and a good evolution. However, blood cultures became positive for the same microorganism 2 weeks after the end of the treatment. Repeat transoesophageal echocardiography showed only a small residual vibrating mass.

18F-FDG PET/CT angiography with myocardial suppression showed a periprosthetic mitral abscess that was able to explain the recurrent endocarditis. The oblique coronal view (a) shows a large residual nodular calcification of the posterior mitral ring. Short-axis, two-chamber and four-chamber fused images in the mitral plane (b–d) show intense focal FDG uptake (SUVmax 13) in the same location [1, 2].

The patient underwent surgery during which a periprosthetic mitral abscess at the inferior ring was completely resected. The antibiotic regimen was repeated and the blood cultures remained negative after 3 months of follow-up.