Imaging in hydrocephalus and spinal dysraphism.

Hydrocephalus and spinal dysraphism are two commonly encountered clinical entities where imaging plays a vital role. Sonography, Computed Tomography and Magnetic Resonance Imaging are the modalities used for the evaluation of hydrocephalus. Ultrasound is useful in small infants with open fontanella, is non-invasive and can be performed at cribside. However, it has limitation in identifying the etiology. CT is the most cost effective modality in the evaluation of hydrocephalus and gives detailed anatomical information. MRI offers the added advantage of multiplanar display and can also assess stenosis/patency of CSF pathways, using phase contrast cine techniques. MRI is the modality of choice for evaluating spinal dysraphism and gives excellent information regarding contents of back mass, spinal cord status and associated anomalies like Chiari malformation. Myelography coupled with CT should be reserved for equivocal cases or in centres where MRI is not available.