Imaging Tests :

Echoencephalography :
Echoencephalography uses ultrasound waves to produce an image of the brain. This simple, painless, and relatively inexpensive procedure can be used in children younger than 2 years because their skull is thin enough for ultrasound waves to pass through. It can be done quickly at the bedside to detect hydrocephalus (previously called water on the brain) or bleeding.

CT and MRI have largely replaced echoencephalography in older children and adults because they produce much better images in these age groups.

Myelography :
In myelography, x-rays of the spinal cord are taken after a radiopaque contrast agent (dye) is injected into the subarachnoid space via a spinal tap. Myelography has been largely replaced by MRI, which produces more detailed images and is simpler and safer to do.

Myelography with computed tomography (CT) is used when doctors need more detail of the spinal cord and surrounding bone than MRI can provide. Myelography with CT is also used when MRI is not available or cannot be done safely (for example, when a person has a heart pacemaker).