Imaging of infectious and inflammatory cystic lesions of the brain, a narrative review

Introduction: Intracranial cysts and cyst-like intracranial lesions are common findings on neuroimaging with a wide range of etiologies. Oftentimes, cystic intracranial lesions are benign but in some parts of the world, infectious etiologies for cystic lesions in the brain are quite common. Prompt identification of the cause of a cystic brain lesion is paramount in determining appropriate treatment if indicated. Areas covered: In this narrative review article, the authors present a comprehensive description of cystic lesions of infectious or inflammatory etiology. Imaging descriptions are provided for each type of cystic lesion as well as several representative images. Expert opinion: The majority of diagnoses may be identified by CT and MR imaging. Yet some pathologies are still unable to be determined through standard imaging techniques and biopsy remains necessary for definitive diagnosis in some cases. Advanced neuroimaging such as metabolic/nuclear imaging and advanced MR hold promise with improved diagnostics but are not often available in geographic regions where these illnesses are endemic.