Inflammatory diseases of the central nervous system are often challenging to diagnose. Necrotizing meningoencephalitis, necrotizing leukoencephalitis, and granulomatous meningoencephalomyelitis have characteristic locations of lesions on histopathologic examination and, therefore, characteristic findings from advanced imaging. Together with clinical signs and clinicopathologic data, these characteristic imaging findings may aid in establishing an accurate antemortem diagnosis. Prompt diagnosis can lead to initiation of treatment using a combination of immunosuppressive drugs.