Cranial magnetic resonance imaging findings in bacterial endocarditis: the neuroimaging spectrum of septic brain embolization demonstrated in twelve patients.

Infective endocarditis (IE) is an elusive systemic disorder that is often associated with neurologic complications. The contribution of brain magnetic resonance imaging (MRI) to the diagnosis of IE and the spectrum of such findings has been only sparsely described previously. The authors report cranial MRI findings in 12 patients with IE. Each of the patients had MRI evidence of cerebral embolization, with multiple brain lesions noted in most patients (n = 1 0). Cortical branch infarction was the most common lesion (n = 8), which usually involved the distal middle cerebral artery tree. The next most common finding (n = 7) was numerous small embolic lesions which typically lodged in the supratentorial gray-white junction, some of which were clinically silent and many of which enhanced (probable microabscesses). Brain hemorrhages were noted in four patients, most commonly subarachnoid hemorrhage (n = 3). Two patients developed multiple frank parenchymal macroabscesses/cerebritis lesions. A previously unreported finding in septic embolization, a stroke that became infected with abscess formation (“septic infarction”), was noted in two patients. MRI showed orbital cellulitis in two patients. Most patients studied with gadolinium showed enhancement of lesions (n = 5/8). The authors conclude that cranial MRI may be a valuable tool in the evaluation of patients with IE. The presence of characteristic cranial MRI lesions, especially of multiple types, may prompt early diagnosis and treatment. Key words: MRI, brain, endocarditis, septic emboli, abscess, stroke, orbital infection.