Dexa
A DEXA scan is a high-precision type of X-ray that measures your bone mineral density and bone loss. If your bone density is lower than normal for your age, it indicates a risk for osteoporosis and bone fractures.
DEXA stands for dual energy X-ray absorptiometry. This technique was introduced for commercial use in 1987. It sends two X-ray beams at different peak energy frequencies to the target bones.
One peak is absorbed by soft tissue and the other by bone. When the soft tissue absorption amount is subtracted from the total absorption, the remainder is your bone mineral density.
The test is noninvasive, fast, and more accurate than a regular X-ray. It involves an extremely low level of radiation.
The World Health Organization (WHO) established DEXA as the best technique for assessing bone mineral density in postmenopausal women. DEXA is also known as DXA or bone densitometry.
What’s the purpose of the scan?
A DEXA scan is used to determine your risk of osteoporosis and bone fracture. It may also be used to monitor whether your osteoporosis treatment is working. Usually the scan will target your lower spine and hips.
Standard X-ray diagnostics used before the development of the DEXA technology were only able to detect bone loss that was greater than 40 percent. DEXA can measure within 2 percent to 4 percent precision.
Before DEXA, the first sign of bone density loss might be when an older adult broke a bone.
