DEXA scan is a method of Bone Mineral Density Assessment.
Bone Mineral Density Assessment is used to:
- Detect the presence of osteoporosis in men and women with particular risk factors
- Screen for osteoporosis, particularly in women making decisions about hormone replacement therapy at menopause
- Predict future fracture risk
- Monitor bone density in those with low normal levels and in those with osteoporosis undergoing treatment
Common uses of this procedure
DEXA scan is used to diagnose osteoporosis on men and women with the following particular risk factors.
- Advanced age
- History of bone fracture
- A small thin frame
- A family history of osteoporosis
- Removal of the ovaries
- Early menopause
- A low calcium diet
- Lack of exercise
- Eating disorders
- Certain medicines (such as steroids or anticonvulsants)
- Alcohol and tobacco
How does it work?
Certified medical personnel conducts the exam. The patient is asked to lie without moving on the scan table but can move normally throughout the procedure. A scanner passes over one area of your skeleton: your lower spine, wrist or hip. A dual energy beam of low dose x-rays pass through that area of your body and is measured by a detector. The scan is repeated for a second skeletal area. DEXA technology works by measuring the amount of x-rays that are absorbed by the bones in your body. The two x-ray energies allow the machine to differentiate between bone and soft tissue, giving an accurate estimation of bone density.
The radiologist produces a report for your physician based on the bone density measurements and your medical history.
The patient does not feel anything during the procedure.
Even though x-rays are used, the amount absorbed by the patient is only about 1/10th of that received from a chest x-ray. Other x-ray procedures have even higher x-ray doses. The x-ray dose from the bone densitometry test is comparable to the naturally occurring radiation exposed to in one week.
Even though the x-ray dose for the bone densitometry test is low, inform the operator if you are pregnant or might be pregnant before your test.
Eat normally on the day of the exam, but avoid calcium supplements the day of your appointment. If possible, wear a two piece outfit so you will not need to disrobe entirely and avoid wearing clothing with metal (buttons, zippers, etc.)