An Image Is Taken
Some types of bone density tests use low level x-rays and others use sound waves to scan your body. This process produces a picture of your bones and takes about 15-20 minutes. Your wrists, spine and hips are common sites that are tested.
According to the National Osteoporosis Foundation (NOF) the most common test is called a DXA, which stands for dual energy X-ray absorptiometry. This specialized machine will measure the density of your bones, i.e. how strong your bones are. NOF states that the scan "compares your bone density to a "young normal" healthy 30-year-old adult with peak bone density (also called peak bone mass). Peak bone density is the point at which a person has the greatest amount of bone that she or he will ever have."
A Report Is Prepared
The National Institutes of Health states that your bone density test results are reported in T and Z scores. The T score tells you how much your bone density deviates from peak bone mass. It is reported as a number that represents how much your bone density is above or below normal. Z scores, which are not used as often, compare your bone density to what is normal in someone your age and body size. It is most commonly used with younger men, premenopausal women and children.
The Results Are Interpreted
If your T score is between +1 and -1, you are considered to have normal bone density. A T score between -1 and -2.5 leads to a diagnosis of osteopenia, which means you are in the beginning stages of osteoporosis. A T score of -2.5 or lower confirms a diagnosis of osteoporosis. A Z-score above -2.0 is considered a normal bone density level.
