Neuroimaging of central nervous system infections

During the past decade, advances have been made in the technology used to image the pediatric central nervous system. Although computed tomography (CT) remains the first line of imaging for the sick child admitted to the emergency room with fever and altered mental status, magnetic resonance imaging (MRI) offers superior soft tissue imaging of central nervous system (CNS) infections and advanced techniques. MRI also is the standard of care for imaging spinal infections. CT remains superior for the detection of calcification and bony detail. With the advent of new MRI sequences such as T2-weighted fluid attenuated inversion recovery (FLAIR), diffusion-weighted imaging (DWI), and magnetic resonance spectroscopy (MRS), we are able to detect early and subtle abnormalities such as the vasculitis accompanying a meningitis and to identify patterns of signal alteration that can help us be more specific about the diagnosis in lesions with similar appearances.