Cranial Ultrasound

Test Overview

Cranial ultrasound uses reflected sound waves to make pictures of the brain and its inner fluid chambers (ventricles). Cerebrospinal fluid flows through these chambers.

This test is most commonly done on babies. It checks for problems from premature birth. It may be used to check problems in the brain and ventricles in babies up to about 18 months old.

Ultrasound waves can't pass through bones. So an ultrasound to check the brain can't be done after the bones of the skull (cranium) have grown together. Cranial ultrasound can be done on babies before the bones of the skull have grown together. Or it can be done on adults after the skull has been opened with surgery. In adults, the test may be done to see brain masses during brain surgery.

Cranial ultrasound for babies

The test looks for possible problems of premature birth, such as:

• Periventricular leukomalacia (PVL). PVL is a condition in which the brain tissue around the ventricles is damaged. This may be caused by a lack of oxygen or blood flow to the brain that may have occurred before, during, or after birth.
• Bleeding in the brain. This includes intraventricular hemorrhage (IVH).

IVH and PVL increase a baby's risk of having disabilities. These may range from mild learning or motor skill delays to cerebral palsy or an intellectual disability.

IVH is more common in premature babies than in full-term babies. When it occurs, it most often happens in the first 3 to 4 days after birth. Most cases of IVH can be found with cranial ultrasound by the first week after birth. But PVL can take several weeks to detect. If PVL is suspected, cranial ultrasound may be repeated 4 to 8 weeks after the birth. Several of these tests may be done to check areas in the brain.

Cranial ultrasound may also be done to check a baby's large or increasing head size. The test can also check for infection in or around the brain (such as from encephalitis or meningitis). Or it may check for brain problems that are present from birth (such as congenital hydrocephalus).

Cranial ultrasound for adults

Cranial ultrasound may be done on an adult to help find a brain mass. Because the test can't be done after the skull bones have fused, it is only done after the skull has been opened during brain surgery.