The Usefulness of Magnetic Resonance Imaging in the Diagnosis of Infectious Endocarditis.

BACKGROUND: Whilst echocardiography is currently the 'gold standard' for the diagnosis of infective endocarditis (IE), it has certain limitations and alternative imaging methods are being sought. The study aim was assess the usefulness of cardiac magnetic resonance (CMR) imaging when diagnosing IE. METHODS: Twenty consecutive patients with diagnosed IE were included in the study. All patients underwent CMR and transthoracic echocardiography, and 16 (80%) underwent also transesophageal echocardiography. RESULTS: CMR revealed vegetations in 15 patients (75%). Following echocardiography, vegetations were identified in 19 patients (95%) and valve perforation was suspected in seven (35%); vegetations were identified by CMR in six (30%) of these patients. Echocardiography identified two patients suspected of perivalvular abscess; in one patient the abscess was diagnosed also by CMR and intraoperatively, but in the second patient neither CMR nor intraoperative examination confirmed this diagnosis. Late gadolinium enhancement (LGE) was reported at CMR in eight patients (40%), associated with an extension of the inflammatory process and myocardium infiltration. The valve insufficiency fraction allowed the degree of insufficiency of the valves affected by inflammatory processes to be estimated. A positive correlation was found between the degree of valve insufficiency assessed with CMR and echocardiography. CONCLUSIONS: CMR may serve as a useful method for diagnosing perivalvular complications in IE patients, although vegetation visualization is limited by the low spatial resolution of the method. CMR may prove superior to echocardiography in evaluating the degree of inflammatory process involvement in the myocardium. The degree of valve insufficiency and its hemodynamic significance can also be assessed.