Early diagnosis of infective endocarditis by brain T2*-weighted magnetic resonance imaging

Abstract

Background: 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. Methods and Results: 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. Conclusions: 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.