2015 ESC Guidelines for the management of infective endocarditis

The Task Force for the Management of Infective Endocarditis of the European Society of Cardiology
ESC GUIDELINES European Heart Journal doi:10.1093/eurheartj/ehv319

The evaluation of patients with infective endocarditis no longer limited to conventional echocardiography, but should include several other imaging techniques such as MSCT, MRI, 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) or other functional imaging modalities.

The main added value of using radiolabelled white blood cell (WBC) SPECT/CT and 18F-FDG PET/CT imaging is the reduction in the rate of misdiagnosed  infective endocarditis, classified in the ‘Possible  infective endocarditis’ category using the Duke criteria, and the detection of peripheral embolic and metastatic infectious events.

Given the recent published data, the Task Force proposes the addition of three further points in the diagnostic criteria

CT = computed tomography; 
FDG = fluorodeoxyglucose; 
HACEK = Haemophilus parainfluenzae, H. aphrophilus, H. paraphrophilus, H. influenzae, Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, Kingella kingae, and K. denitrificans; 
IE = infective endocarditis; 
Ig = immunoglobulin; 
PET = positron emission tomography; 
SPECT = single photon emission computerized tomography

18F-FDG PET/TC positive in
thrombi, soft atherosclerotic plaques, vasculitis, primary cardiac tumours, cardiac metastasis from a non-cardiac tumour, post-surgical inflammation and foreign body reactions.
Limitations to the use of 18F-FDG PET/CT are represented by localization of septic emboli in the brain, due to the high physiological uptake of this tracer in the brain cortex, and to the fact that at this site, metastatic infections are generally ,5 mm

Radiolabelled WBC SPECT/CT
is more specific for the detection of infective endocarditis and infectious foci than 18F-FDG PET/CT and should be preferred in all situations that require enhanced specificity