Cerebrospinal fluid, commonly abbreviated CSF, is a clear, colorless liquid that circulates through the ventricles of the brain, around the surface of the brain and spinal cord within the subarachnoid space. It serves to cushion the brain against injury, remove waste products, and maintain a stable chemical environment. On ultrasound, CSF appears anechoic (dark) because it is a simple fluid, and it is most commonly visualized within the brain’s ventricular system during neonatal cranial ultrasound. Changes in the amount or flow of CSF can lead to conditions like hydrocephalus, where the ventricles enlarge due to impaired drainage, or ventriculitis, where the fluid becomes infected and may appear echogenic.
Sonography Term