Other Imaging Modalities in Infective Endocarditis Diagnosis

Abstract

N

Current Status of Molecular Imaging in Infections

“…In order to avoid potential sources of false-positive findings in PET or PET/CT studies some considerations should be take into account in the imaging interpretation [185]. Variable focal of diffuse physiological [ 18 F]FDG uptake is often observed in the normal myocardium (mainly in the left ventricle) of fasting non-diabetic patients (6-12 hours to overnight) with normal glucose levels [185,186]. Many factors such as patients' age, fasting time, blood glucose levels, and a low-carbohydrate diet may influence myocardial [ 18 F]FDG uptake [185,187,188].…”

“…Variable focal of diffuse physiological [ 18 F]FDG uptake is often observed in the normal myocardium (mainly in the left ventricle) of fasting non-diabetic patients (6-12 hours to overnight) with normal glucose levels [185,186]. Many factors such as patients' age, fasting time, blood glucose levels, and a low-carbohydrate diet may influence myocardial [ 18 F]FDG uptake [185,187,188]. Some approaches might be used to decrease myocardial [ 18 F]FDG uptake including lowcarbohydrate diet [189] and very high-fat, low-carbohydrate, protein-permitted meal followed by fasting for 3-6 hours [190] before tracer injection [185,187].…”

“…Many factors such as patients' age, fasting time, blood glucose levels, and a low-carbohydrate diet may influence myocardial [ 18 F]FDG uptake [185,187,188]. Some approaches might be used to decrease myocardial [ 18 F]FDG uptake including lowcarbohydrate diet [189] and very high-fat, low-carbohydrate, protein-permitted meal followed by fasting for 3-6 hours [190] before tracer injection [185,187]. Alternatively, unfractionated heparin (50 IU/kg iv) which acts activating lipoprotein lipase and hepatic lipase, enhances plasma lipolytic activity and elevates plasma levels of FFA, could be administered before [ 18 F]FDG injection [185,191,192].…”

“…Some approaches might be used to decrease myocardial [ 18 F]FDG uptake including lowcarbohydrate diet [189] and very high-fat, low-carbohydrate, protein-permitted meal followed by fasting for 3-6 hours [190] before tracer injection [185,187]. Alternatively, unfractionated heparin (50 IU/kg iv) which acts activating lipoprotein lipase and hepatic lipase, enhances plasma lipolytic activity and elevates plasma levels of FFA, could be administered before [ 18 F]FDG injection [185,191,192]. According to the SNMMI/ASNC/SCCT Guidelines [193] patients should be prepared with a fat-enriched diet lacking carbohydrates for 12-24 h prior to the scan, a 12-18-h fast, and/or the use of intravenous heparin approximately 15 min prior to [ 18 F]FDG injection [187].…”

“…The increased metabolic activity along the posterior aspect of the heart, where lipomatous hypertrophy of the interatrial septum may appear as a fat-containing mass with increased [ 18 F]FDG uptake, could be another potential counfonding factor in the interpretation of PET/CT results [185,194]. Several different pathologic conditions such as active thrombi [186], soft atherosclerotic plaques [190], vasculitis [195], primary cardiac tumors [196], cardiac metastasis from a noncardiac tumor [197], postsurgical inflammation [198], and foreign body reactions [199] can mimic the pattern of focally increased [ 18 F]FDG uptake that is typically observed in IE [185,187]. Therefore they should be considered in the differential diagnosis and excluded before diagnosis IE [185,187].…”