The DEXA scan (Dual X-ray Absorptiometry)
Is any preparation necessary?
No – no preparation is required for this examination.
However, if you have undergone an examination that involved the use of a contrast material, such as a barium enema or a CT scan, you must wait for 14 days before undergoing a bone density scan.
What will happen at my appointment?
• Please bring the results and charts of any previous bone density scans you have undergone.
• Please do not wear clothing that contains metal e.g. zips.
• If you are to undergo a bone density scan of your forearm, you will need to remove any bracelets.
• If there are any metal implants in your body, you will need to inform the Radiographer.
The scanning procedure:
Bone density is measured with X-ray equipment using the DEXA method. You will be asked to lie down on your back and the area to be examined will be positioned under the scanner, for example the lumbar spine, the hip or the forearm.
How will I understand the results and what might I need to do?
Your scan results will be sent by post to your home, your GP or consultant within approximately 7 working days of the examination. You will need to discuss the results of your scan with your GP.
The DEXA scan evaluates Bone Mineral Density (BMD). The results predict the likelihood of fracture. BMD is generally measured in the spine and hip. The DEXA scan calculates bone density based on the amount of radiation absorbed by the bone. It compares your personal information obtained during the examination (bone density, age, height and weight) with the average for the general population. The severity of the disease and the need for treatment are determined accordingly.
The scan results are kept in your medical notes so that they can be compared with future DEXA scans.
What will the Bone Density measurements indicate?
The DEXA method is used to examine the bone density (calcium content) of the spine, the hip joint and the root of the palm. The scan can identify bone loss even in the very early stages of osteoporosis. It calculates the likelihood of developing a fracture and the rate at which calcium is being lost.