Bone density scanning, also called dual-energy x-ray absorptiometry (DXA) or bone densitometry, is an enhanced form of x-ray technology that is used to measure bone loss.
DXA is today's established standard for measuring bone mineral density (BMD).
By accurately measuring bone density, a DEXA scan can tell you whether you have osteoporosis, whether you are likely to develop osteoporosis and whether you might benefit from medication to slow bone loss.
When the results from your scan come in, your doctor will likely give you two numbers.
The first is a T-score. This compares your results to the bone density of a healthy 30-year-old:
- A T-score greater than -1 is considered normal
- A T-score between -1 and -2.5 indicates osteopenia
- A T-score lower than -2.5 indicates osteoporosis
The second number provided with your results is a Z-score, which compares your bone density to the average for someone of your age, weight, sex and ethnicity. A Z-score over 2.0 is considered normal, while a Z-score below -1.5 could indicate something besides age is contributing to bone loss.
Depending on the results of your DEXA scan, you and your doctor may decide you need to take further steps to protect your bone health.