Molecular Imaging in the Diagnosis of Infectious Endocarditis - the Role of PET and SPECT

Abstract 18-fluorine-fluorodeoxyglucose positron emission computed tomography (18F-FDG PET/CT) and singlephoton emission computed tomography (SPECT) using radiolabeled white blood cells (WBC) are non-invasive techniques widely used in the diagnosis of infections, like endocarditis. The aim of our paper was to provide a systematic review of the published data on the use of 18F-FDG PET/CT and SPECT in infective endocarditis (IE). A comprehensive literature search of the PubMed/ MEDLINE, Scopus, Embase and Cochrane library databases was conducted to find relevant published articles about the diagnostic performance of SPECT using WBC and 18F-FDG PET/CT in the diagnosis of infectious endocarditis. Twenty papers were included, with a total of 1,154 patients (166 studies with WBC SPECT and 988 with 18F-FDG PET/CT). From the analyses of the studies, the following results were obtained: both SPECT and PET/CT had good diagnostic accuracy in the study of endocarditis. 18F-FDG PET/CT had good specificity (85.8%) and lower sensitivity (68%), with high heterogeneity among the studies; WBC SPECT/ CT had an overall sensitivity of 80% and specificity of 98%. Specific preparations for PET/CT can affect the diagnostic accuracy of the test. Both 18F-FDG PET/CT and WBC SPECT are useful for the diagnosis of IE, and WBC SPECT appears to be slightly more specific than 18F-FDG PET/CT. A specific diet could influence the diagnostic performance of PET/CT.