Cardiac Imaging in the Diagnosis of Infective Endocarditis

With increasingly complex patients, multimodality imaging is often required for expeditious diagnosis and appropriate management of patients with infective endocarditis. Transthoracic echocardiography is the initial imaging modality to assess for vegetations and define hemodynamic consequences. Transesophageal echocardiography is pursued in high-risk patients and in patients with suspected prosthetic valve or cardiac device related infective endocarditis. In addition to assessing for vegetations and valvular destruction, echocardiography can identify complications such as abscesses and pseudoaneurysms. Cardiac computed tomography (CT) can also delineate these invasive complications and may also identify noncardiac sites of infection. In addition, cardiac CT can assess the coronary arteries and help with planning repeat cardiac surgery. Finally, F18-flurodeoxyglucose (F18-FDG) PET-CT can be used to image glucose utilization of inflammatory cells at the site of infection. F18-FDG PET-CT is most accurate in identifying locally invasive complications in patients with prosthetic valve endocarditis and may reveal extracardiac foci of infection. In conclusion, the diagnosis of infective endocarditis is often challenging, and delays in treatment lead to poor patient outcomes. This chapter highlights the strengths and limitations of imaging modalities to inform appropriate test selection in the diagnosis of management of infective endocarditis.