Acute Viral Encephalitis Neuroimaging Spectrum: Clinical Correlation

Document Type

Conference Proceeding - Restricted Access

Publication Date


Publication Title

ASNR 2019 Proceedings


Purpose Viral encephalitis can be a challenging diagnosis. Neuroimaging guides diagnosis, early intervention, and improves clinical outcomes. We present classical imaging features of common and uncommon cases of viral encephalitis. Materials and Methods CT and MRI brain imaging findings were reviewed from confirmed cases of viral encephalitis. Findings will be discussed for each etiology of viral encephalitis including herpes simplex virus (HSV), West Nile, and influenza encephalitis, and progressive multifocal leukoencephalopathy (PML). Results HSV encephalitis presents with abnormal signal in the temporal lobes, insular cortex, and limbic region on MRI. PML presents in immunocompromised patients with involvement of U-fibers and T2 prolongation in subcortical white matter. MRI in West Nile encephalitis demonstrates T2 hyperintensity in the basal ganglia, brainstem, and mesial temporal lobes. MRI findings in influenza encephalitis is not well studied and may demonstrate multifocal areas of diffusion restriction with corresponding low T1 and increased T2 signal abnormality involving bilateral hippocampi, periaqueductal gray matter, and superior colliculus. Conclusions The cause of encephalitis may be unknown in some patients, although it is often viral in etiology. Neuroimaging can identify potential complications and differentiate from other causes of altered mental status. Neuroradiologists should be aware of these findings to determine a diagnosis in an efficient manner.

First Page


Last Page



American Society of Neuroradiology. ASNR 2019 Annual Meeting, May18-23, 2019. Boston MA. Meeting Abstract: 2572.

This document is currently not available here.