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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.

Cranial ultrasound for babies

Cranial ultrasound can only be done on babies before the bones of the skull have grown together. The test looks for possible problems of premature birth, such as periventricular leukomalcia (PVL) and bleeding in the brain (intraventricular hemorrhage, or IVH). These problems can increase a baby's risk of having disabilities.

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.

Why It Is Done

In babies, cranial ultrasound usually is done:

  • As part of routine tests in premature babies. The test is used to find bleeding in the brain, such as intraventricular hemorrhage (IVH).
  • To look for any problems or to look for periventricular leukomalacia (PVL).
  • To screen for brain problems that may be present from birth. For example, it may look for congenital hydrocephalus.
  • To check a head that may be growing too large.
  • To look for infection or abnormal growths in or around the brain.

How To Prepare

In general, there's nothing you have to do before this test, unless your doctor tells you to.

If an older baby is having the test, it may help if the baby is a little hungry. You can feed your baby during the test. This may help calm your baby so he or she will hold still during the test.

How It Is Done

The test is often done at the baby's bedside in the neonatal intensive care unit (NICU).

Your baby will lie on his or her back. A device called a transducer is moved across the soft spot on top of the head. This spot is called the fontanelle. You may be asked to hold your baby during the test. Pictures of the brain and inner fluid chambers (ventricles) can be seen on a video screen.

How long the test takes

The test usually takes 15 to 30 minutes.

How It Feels

This test doesn't cause any pain or discomfort for your baby.


There are no known risks from having this test.


Cranial ultrasound


The size and shape of the brain look normal.

The size of the brain's inner fluid chambers (ventricles) is normal.

Brain tissue looks normal. There are no signs of bleeding, suspicious areas (lesions), abnormal growths, or infection.


Bleeding in the brain may be present. This may be a sign of intraventricular hemorrhage (IVH). The test may be repeated to keep track of the bleeding or to look for problems caused by the bleeding.

Suspicious areas or lesions around the brain's ventricles may be seen. This may be a sign of periventricular leukomalacia (PVL).

The brain and ventricles may be enlarged from the buildup of too much cerebrospinal fluid (CSF). This may be a sign of hydrocephalus.

Abnormal growths may be present. This may be a sign of a tumour or cyst.

Suspicious findings may be present. This may be a sign of encephalitis or meningitis.


Current as of: December 18, 2022

Author: Healthwise Staff
Clinical Review Board
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