Imaging tests for assessment of infective endocarditis
| Imaging test | When to consider | Advantages | Limitations |
|---|---|---|---|
| Transthoracic echocardiography (TTE) | Suspected infective endocarditis in patients with risk factors | Widely available Relatively fast Provides hemodynamic information Noninvasive | Decreased sensitivity for abscesses Can miss small vegetations Limited sensitivity for prosthetic valve infective endocarditis Operator-dependent |
| Transesophageal echocardiography (TEE) | Suspected infective endocarditis despite negative or inconclusive TTE Suspected infective endocarditis in patients with prosthetic valves | Higher sensitivity than TTE for native-valve infective endocarditis, especially mitral valve infection Higher sensitivity than TTE in the presence of prosthetic valves or cardiac implanted electronic device (CIED) No radiation involved | Patients must fast before test Cannot be used if oropharyngeal or esophageal structural abnormalities are present Sensitivity still decreased if prosthetic valve or CIED is present Anesthesia-associated risk Operator-dependent |
| 4-dimensional computed tomography (4D CT), with or without coronary angiography | Suspected infective endocarditisin patients with negative orinconclusive TTE andcontraindications to TEE Perioperative assessment ofcoronary vasculature and aortictree in patients with knowninfective endocarditis | Can detect local extension ofinfection, including abscess,fistula, and pseudoaneurysm Can incidentally detectpulmonary emboli Alternative to coronarycatheterization for preoperativeevaluation | Can miss small valvular vegetations and perforations Iodinated contrast may exclude patients with renal dysfunction or iodine sensitivity Radiation exposure Arrhythmia reduces sensitivity due to motion artifact |
| Fluorodeoxyglucose positron emission tomography (FDG-PET) | Suspected infective endocarditisin patients with prosthetic valveor cardiac implanted electronicdevices and negative orinconclusive echocardiography Patients with persistentbacteremia and negative CTto identify nidus ofinfection for source control | Identifies metastatic sites of infection Increases sensitivity of Duke criteria, especially in patients with cardiac implanted electronic devices Can identify source of bacteremia Better than echocardiography at diagnosing intracardiac abscesses and pseudoaneurysms | False positives, particularly = 3months after cardiac surgery orwith vasculitis, tumors, foreignbodies, postsurgical inflammation False-negatives with antibioticsfor several days Limited diagnostic precision innative valve infective endocarditis Limited ability to evaluate infectionin brain, gingiva, kidneys Dietary carbohydrate restriction12–24 hours before study Expensive, limited availability |
| Leukocyte scintigraphy | Same as for FDG-PET | More specific than FDG-PET | Long study duration Expensive, limited availability Radiation exposure |
| Cerebral magneticresonance imaging(MRI) | Assess for mycotic aneurysm in patients otherwise deemed candidates for surgical intervention Assess for cerebral hemorrhage, which may affect management (surgery, anticoagulation) | More sensitive than CT for detecting intracranial lesions Can lead to reclassification of patients (by adding a minor criterion), especially in those without neurologic symptoms | Difficult in unstable patients Contraindicated in patients with noncompatible metal hardware Cannot be done with gadolinium enhancement in patients with contraindications (acute renal failure, chronic kidney disease with glomerular filtration rate < 30 mL/min/1.73 m2, dialysis) |
| Cardiac MRI | Quantify valvular regurgitation in patient with poor echocardiography images Assess intracardiac spread of disease in patient unable to receive contrast and with poor echocardiography images | May be more sensitive than echocardiography for detecting vegetations | Unclear if better than CT Contraindicated in patients with noncompatible metallic hardware |