A bone density scan, also known as a DXA scan, uses small dose of X-ray radiation and a computer to measure the amount of calcium present in your bones. A DXA scan looks for signs of fragile bones (osteoporosis), which have a low density. The results of the scan help to: 1. estimate your risk of fractures in different bones, for example hip, wrist or bones of the spine; 2. monitor how well treatment for osteoporosis is working. The procedure is quick and painless.
The results of a DXA scan for bone density use a system called a T-score. The T-score involves comparing a person's scan with the bone density of a healthy young adult of the same sex. The World Health Organization (WHO) provided certain cut-off points to define the bone density levels. For more details click here