Magnetic resonance imaging of amebic encephalitis due to Balamuthia mandrillaris

The MRI is from a 2-year-old boy who presented with fevers, obtundation, and seizures. The T2-weighted images (panels A and B) show bilateral hemispheric lesions (arrows) in the right posterior parietal lobe (panel A) and in the left caudate nucleus (panel B). The pre-gadolinium T1-weighted sequence in the sagittal plane (panel C) shows subtle findings that become more apparent as enhancing lesions (arrows) in the post-gadolinium sequence (panel D). The ependymal enhancement (arrowhead) confirms the presence of ependymitis. The diagnosis of amebic meningoencephalitis due to Balamuthia mandrillaris was confirmed by surgical biopsy.