Early Diagnosis of Infective Endocarditis by Brain T2*-Weighted Magnetic Resonance Imaging

Because infective endocarditis (IE) carries a high risk of morbidity and mortality, rapid diagnosis and effective treatment are essential to achieving a good patient outcome. However, the diagnosis of IE is often difficult in patients presenting with nonspecific clinical manifestations. An association between IE and hypointense signal spots on brain T2*-weighted magnetic resonance imaging (MRI) has been reported, but the clinical significance remains unclear.

To assess the clinical importance of silent lesions in the brains of IE patients, hypointense signal spots detected on their brain T2*-weighted MRI scans were investigated in a retrospective review of 44 consecutive patients with definite or suspected IE evaluated by MRI between June 2006 and January 2014. Hypointense signal spots on T2*-weighted MRI were detected in 37 (84%) patients; of these, 21 (46%) had ischemic lesions, 10 (22%) had subarachnoid hemorrhage, 4 (9%) had intraparenchymal hemorrhage, and 4 (9%) had infectious aneurysm. The hypointense signal spots on T2*-weighted images were preferentially distributed in cortical areas.

T2*-weighted hypointense signal spots are highly frequent in patients with IE and their presence may be informative in the monitoring of IE-associated brain lesions, even those that are neurologically asymptomatic. The strong association between IE and T2*-weighted hypointense signal spots supports the need to consider additional criteria in the diagnosis of IE.