Dual-energy X-ray Absorptiometry (DXA) scans use low dose X-Rays to measure bone mineral density and are commonly used to diagnose or assess a patient’s risk of osteoporosis and fractures.
What is a bone density DXA scan and what does it cover?
A bone density scan assesses bone’s turnover: a natural process of bone thinning. The scan uses a small dose of radiation. We measure how much energy is absorbed by the bone; therefore measuring their bone mineral density (BMD). The results will determine whether a patient’s bone density is adequate to their age and gender.
At a certain age we are expected to lose bone density. If the scan determines that the BMD decreased below the safe level then supplementation or treatment is required.
DXA scans are based on lumbar spine, neck of femur and forearm measurements. For more accurate results we will only scan two sites. There is only one instance (hyperparathyroidism) where all three sites are included.
Why is a DXA scan required?
A DXA scan is not essential to start supplementation, bone protection or treatment; however, it is helpful to assess BMD before starting any medication. We can determine what the patient’s bone mineral content is and then monitor it throughout their treatment. Please note a complete bone turnover can take up to 7 years; bone density changes slowly, therefore frequent scans are not recommended.
Where is this scan performed?
Our service is currently located at the LGH Radiology Department.
Contact details for further information
Queries can be directed to 0116 258 8765 – Option 8. Clinical questions will be directed to a clinical lead where one is available.
Why are patients referred for this scan?
Losing bone density is a natural process; however, some patients have additional risk factors that may speed up this process. This scan will determine whether the patient is at risk and needs to be monitored to maintain good bone health for longer.
Scan duration
Patients are given 20 minute appointments. Longer appointments are available for patients with physical difficulties. During the appointment we will perform 1-4 scans; they only take about 1 minute each, however, the patient may need more than one scan. If you believe that your patient requires more time please indicate this on the referral form.
What results to expect after the scan and how to access them?
Normal – bone density is normal for the patient’s age and gender. No further scan is required unless the patient is at risk due to their conditions or medications.
Osteopenia – the patient’s bone density is lower than it should be. Because losing bone density is a natural process we will all get to this stage eventually. The patient could be referred for another scan in 3-5+ years. Note: try to encourage patients to reduce risk factors (if possible) and encourage physical exercises (if safe to do so). Dietary advice could also impact patient’s bone health, especially when combined with body weight exercises.
Osteoporosis – BMD and trabecular pattern has reduced to the point where osteoporosis (a disease) is present. This will require a treatment with Bisphosphonates (BP) and follow up appointments. We recommend that the patient is scanned after 3 years. Note: the effectiveness of BP can be assessed with a blood test for bone markers; this can be performed every 6 months.
After the scan
Patients are not given any medication. The scan is safe and doesn’t carry any side effects so patients will be able to go about their day as normal.
Inclusion and exclusion criteria
Inclusion criteria:
- Please refer to the request form or ICE/Nerve Centre.
Exclusion criteria:
- Patients who do not have any risk factors and do not meet the inclusion criteria
- Patients above 90 years of age
- We will also be unable to scan:
- Sites with Scoliosis, severe degenerative changes of the spine, metastatic bone disease etc.
- Bone that has been broken previously (natural bone turnover no longer present)
- If all 3 sites (lumbar spine, femurs, forearms) have been disturbed and none of them represent natural bone turnover anymore.
- Patients who require a hoist (due to physical structure of the scanner it is not possible to use a hoist)
Additional information for referrers
- FRAX/NOGG has recently changed, please refer to those for treatment recommendations and scan guidelines
- Drug holidays - DXA scan is not essential to take a break from biphosphonates (BP). It is important not to prolong BP duration due to side effects. Please review NOGG statement.
