What is a DXA Scan?

A bone density scan, or DXA (dual-energy X-ray absorptiometry) scan, is an imaging test that measures bone density (the amount of material in the bones). A DXA scan uses X-rays to take pictures of different bones in the body, depending on your child’s age and medical needs.

How Does a DXA Scan Work?

The DXA scan machine uses low-energy X-rays to take pictures of the bones. Your child will receive a very small dose of radiation through these X-rays, but the dose is very safe.

How Can I Prepare My Child for the DXA Scan?

  • Have your child wear loose, comfortable clothes without metal. This includes clothing without zippers, hooks or buttons. If this is not possible, your child can change into soft hospital pajamas after checking in at the front desk.
  • Your child can eat and drink as normal on the day of the scan.
  • Please arrive to MassGeneral Hospital for Children at least 15 minutes before the scheduled appointment time.

How Long Does the DXA Scan Take?

The DXA scan takes about 10 minutes. After the scan, you and your child can go back to your usual activities.

What Can I Expect on the Day of the DXA Scan?

  • After you check in at the front desk, an X-ray technician (person who operates the X-ray machine) will take you and your child to the X-ray room.
  • If needed, your child will change into soft hospital pajamas.
  • Your child will lay down on a padded table with foam pillows to help him feel more comfortable. The pillows also help place his body into the proper position.
  • The X-ray machine will be above or beside the table. It will take pictures of your child’s body. The machine will make beeping and whirring sounds, but it will not touch your child. The DXA scan does not hurt.

When Will I Get the DXA Scan Results?

The DXA scan results will be sent to your child’s doctor about 1-2 weeks after the scan. Your child’s doctor will call you with the results.

What is a Z-Score?

  • Z-score is what doctors use to evaluate your child’s bone density. A Z-score compares your child’s bone density to the bone density of other children of the same age and sex.
  • An average Z-score is 0. Most children will have a Z-score between -2 and 2. Your child’s doctor will explain the Z-score and answer any questions you have.