Imaging of Uncommon Bacterial, Rickettsia, Spirochete, and Fungal Infections.

This article reviews uncommon bacterial (brucellosis, actinomycosis, neuromelioidosis, nocardiosis, whipple disease, and listeriosis), Rickettsia, spirochete (neurosyphilis and Lyme disease), and fungal (mucormycosis, aspergillosis, candidiasis, cryptococcosis, and Cladophialophora bantiana) diseases affecting central nervous system (CNS), focusing primarily on their cranial manifestations. These infections often show a variety of neuroimaging features that may be similar or differ from typical pyogenic bacterial meningitis and abscess. Familiarity with these patterns is essential for timely recognition and initiation of appropriate management. Neuroimaging is also useful for identifying complications of CNS infections and follow-up evaluation after initiation of treatment.