Bone mineral densitometry

Bone mineral densitometry scan Bone mineral densitometry scan  

What is bone mineral densitometry?

Bone mineral densitometry, or BMD, is a low energy x-ray that measures the level of minerals in your child’s bones. Sometimes this x-ray is called a DPX or DXA scan.

How is BMD done?

A nuclear medicine technologist will do the BMD. They will first explain the x-ray to you and ask some questions about your child’s bone health.

If your child has any metal or plastic on or under their clothes, they will change into a hospital gown. Otherwise, they can continue wearing their regular clothes.

They will then lie on their back on a bed.

An x-ray tube will move above them to do the scan, but it will not touch them. Your child must stay still to make sure the x-ray is clear.

Note: Your child will not need any injection (needle) for this scan.

How long does the BMD take?

The BMD takes about 15 to 30 minutes.

Will I be able to stay with my child during the BMD?

One parent or guardian can stay in the room during the scan, but no other children are allowed.

Does my child need to do anything special to prepare for the scan?

No, your child can eat and drink as usual.

My child recently took x-ray dye for another scan. Can they still have a BMD?

Yes, but your child cannot have the BMD right away. They must wait:

  • two days if they took the dye through an IV (a thin tube going into a vein in their arm or hand)
  • two weeks if they took the dye by mouth.

What if my child needs another type of nuclear medicine test on the same day as the BMD?

Have your child do the BMD first to make sure the x-ray gives an accurate picture of their bones.

Does the x-ray carry any risks?

A BMD involves giving a very small amount of radiation to your child. The nuclear medicine team will discuss this with you when you and your child arrive for the x-ray. You might also find it helpful to read this information about nuclear medicine​ from the Alliance for Radiation Safety in Pediatric Imaging.

How soon after the x-ray will I get the results?

A nuclear medicine doctor will send a report to your family doctor or paediatrician (child's doctor) within one or two working days of the scan. Please contact your family doctor to get the results. The nuclear medicine technologist cannot give the results of the scan.

Key points

  • BMD is a low-energy x-ray to measure the amount of mineral in your child’s bones. It takes 15 to 30 minutes.
  • If your child has taken x-ray dye for another scan, they must wait before having the BMD.
  • If your child has a number of scans on the same day, the BMD must be done first.
  • A nuclear medicine doctor will send the results of the scan to your family doctor or paediatrician (child's doctor) within two working days. The person who does the scan cannot give the results.​


​​Mandy Kohli, Clinical Co-ordinator, Nuclear Medicine

​At SickKids

If you have any questions or concerns about the x-ray or if you need to change your appointment, please call the Nuclear Medicine Department at 416 813 6065.​ 


Alliance for Radiation Safety in Pediatric Imaging (2013). Image Gently: Nuclear Medicine - What can I do as a parent?