These tests measure the mineral density in bones and can provide a diagnosis of osteoporosis before the bones become so weak that they break. With early detection a treatment plan can be initiated to minimize further bone loss and to strengthen bone tissue.
There are two types of bone mineral density (BMD) scans:
DEXA uses only one-tenth the radiation of standard X-ray. While the patient rests on a padded table, an X-ray scanning machine moves over the body and captures images of the hip, spine, or entire body. The scan takes about 20 minutes to complete.
Peripheral Bone Density Tests measure BMD in less than a minute by passing sound waves through a wrist, finger, or heel. Peripheral bone density tests are performed with portable devices that make measuring BMD convenient and inexpensive.
In general, this testing is recommended for women 65 and older along with younger postmenopausal women who have further risk factors for osteoporosis, including:
Neither test requires any special preparation. Unlike a bone scan, bone density testing does not involve the administration of radioactive contrast material into the bloodstream.
The results of a DEXA scan are compared to the "normal" range for people of the same age, sex and race, and to the maximum bone density possible (found in young adults).
Both tests are painless, noninvasive, and have no side-effects.
A bone density scan can indicate what your current bone mineral density is. Repeated scans (a year or two apart) can tell if you are gaining, losing or just maintaining bone.
A new urine test utilizes the two most specific markers of bone resorption – the collagen crosslinks pyridinium/pyridinoline (PYD) and deoxypyridinium/deoxypyridinoline (DPYD or DPD) – to identify elevated levels of bone loss before excessive damage occurs. This profile enables regular testing of women for resorption rates, allowing treatment intervention at its most effective – before bone loss has occurred. It also allows easy and rapid monitoring of treatment effectiveness. As valuable as bone scan results can be in the definitive diagnosis of osteoporosis, the evaluation cannot be performed often enough for patients who are losing bone at a fast rate.
In premenopausal women, estrogen produced in the body maintains bone density. Following the onset of menopause, bone loss increases each year and can result in a total loss of 25-30% of bone density in the first five to ten years after menopause. Your doctor can help you decide when and if you need a bone density test.