Bone Densitometry

Bone Densitometry or a Bone Density Scan (DXA) is an enhanced form of x-ray technology that can measure bone loss and bone mineral density (BMD).

DXA can be used to diagnose osteoporosis and other conditions causing bone mineral loss. It is also helpful in tracking the treatment of these conditions. DXA allows the risk of fracture to be calculated. A radiologist, a physician specifically trained to supervise and interpret radiology examinations, analyzes the images. DXA scans are also interpreted by other physicians such as rheumatologists and endocrinologists.

Test results are reported in the form of two scores:

T score — This number shows the amount of bone the patient has compared with a young adult of the same gender with peak bone mass. A score above -1 is considered normal. A score between -1 and -2.5 is classified as osteopenia (low bone mass). A score below -2.5 is defined as osteoporosis. The T score is used to estimate the risk of developing a fracture.

Z score — This number reflects the amount of bone the patient has compared with other people in their age group and of the same size and gender. If this score is unusually high or low, it may indicate a need for further medical tests.

Small changes may normally be observed between scans due to differences in positioning and usually are not significant.