This page explains about DEXA scans and what to expect when your child comes to Great Ormond Street Hospital (GOSH) for the scan.
What is a DEXA scan?
A DEXA scan is used to measure the density or strength of bones. DEXA stands for Dual Emission or Energy X-ray Absorptiometry. It works by aiming two X-ray beams at a bone, which are either absorbed or pass through the bone.
The denser the bone, the fewer X-rays can pass through. A computer records the X-rays and calculates a figure for the mineral density of the bone scanned.
Are there any alternatives?
Various types of scan such as CT, ultrasound and X-rays can show the size and shape of your child’s bones, but not their density. The results of the scan are then used to plan your child’s treatment.
When you receive your appointment letter
If you are unable to keep this appointment, please inform the department at least two weeks beforehand. Sometimes, we can offer the appointment to another child on the waiting list. As so many children and young people need to use our services, we have had to introduce a policy where if a child cancels or does not attend two appointments in a row, we will close their referral and inform their GOSH consultant.
One week before the appointment
If your child is likely to need a hoist during the appointment, please telephone us before the appointment so that we can make sure this is ready for you.
The day of the scan
Please arrive at the Radiology (X-ray) reception desk at the time stated in your child’s appointment letter.
There is no preparation needed for this scan. A radiographer will take you and your child down to the DEXA scanner. Your child will not need to get undressed for the scan. However, they should wear clothes containing as little metal, such as zips or buttons, as possible as this interferes with the scan.
You will be able to stay with your child for the entire scan. We will measure your child’s height and weight when you come down to the DEXA scanner. Afterwards, your child will need to lie flat on the scanning bed.
During the scan, the scanner arm will move over your child but will not touch them. Your child will need to lay still for the scan but this usually only lasts for a couple of minutes or so. The entire process lasts around 15 minutes.
After the scan
If your child is not having any further scans or tests, you will be free to go home. If they have a clinic appointment after the DEXA scan, we may ask you to take a printed copy of the report with you. The radiographer will also send a copy of the report to your child’s doctor.