Role of imaging in CNS infections

Neuroinfections are seen in both adults and children. These can result in serious morbidity and if left untreated and/or associated with comorbidities can be life threatening. Cross-sectional imaging like computed tomography (CT) and magnetic resonance imaging (MRI) are advised by the clinicians for the diagnosing, confirmation of the diagnosis, assess any complications of the infection, and also for follow up. Though CT is the initial imaging investigation commonly asked by the clinician, due to its lesser soft tissue resolution, early brain changes may not be seen on CT. MRI has better soft tissue resolution with no ionizing radiation to the patient and helps in detecting the early signs of infection. Appropriate MRI, not only helps the radiologist to reduce the number of possibilities of the causative organism but also differentiates tumors from infection. However, CT is useful to assess the bony changes and also easily available and affordable cross-sectional imaging modality worldwide. The review summarizes the approach of the radiologist to central nervous system (CNS) infections and their typical imaging characteristic features.