Osteoporosis Diagnosis
Certain types of doctors may have more training and experience than others in
diagnosing and treating people with osteoporosis. These include a geriatrician, who
specializes in treating the aged; an endocrinologist, who specializes in treating diseases
of the body's endocrine system (glands and hormones); and an orthopedic surgeon, who
treats fractures, such as those caused by osteoporosis.
Test used in Osteoporosis Diagnosis
- Bone mineral density (BMD) testing -- as performed in dual-energy x-ray absorptiometry
(DEXA) -- measures the demineralization of the bones. This has become the gold standard
for evaluation for osteoporosis. BMD testing should be performed on all postmenopausal
women with fractures, all women under 65 with an additional risk factor for osteoporosis
(besides menopause), and all women 65 and over.
- A spine CT can show demineralization. Quantitative computed tomography (QCT) can
evaluate bone density, but is less available and is more expensive than DEXA.
- A spine or hip x-ray may show fracture or vertebral collapse in severe cases.
- Measuring the amount of calcium in your urine can provide some evidence of increased
bone turnover, but is of limited value. A number of newer tests to evaluate bone turnover
are becoming available, including measurement of urinary N-telopeptide (Osteomark). In the
future, these may enhance your physician's ability to diagnose early osteoporosis.
More detailed information about Osteoporosis Diagnosis
Before making a diagnosis of osteoporosis, the doctor usually takes a complete medical
history, conducts a physical exam, and orders x rays, as well as blood and urine tests, to
rule out other diseases that cause loss of bone mass. The doctor may also recommend a bone
density test. This is the only way to know for certain if osteoporosis is present. It can
also show how far the disease has progressed.
Several diagnostic tools are available to measure the density of a bone. The ordinary x
ray is one, though it's the least accurate for early detection of osteoporosis, because it
doesn't reveal bone loss until the disease is advanced and most of the damage has already
been done. Two other tools that are more likely to catch osteoporosis at an early stage
are computed tomography scans (CT scans) and machines called densitometers, which are
designed specifically to measure bone density.
The CT scan, which takes a large number of x rays of the same spot from different
angles, is an accurate test, but uses higher levels of radiation than other methods. The
most accurate and advanced of the densitometers uses a technique called DEXA (dual energy
x-ray absorptiometry). With the DEXA scan, a double x-ray beam takes pictures of the
spine, hip, or entire body. It takes about 20 minutes to do, is painless, and exposes the
patient to only a small amount of radiation--about one-fiftieth that of a chest x ray.
Doctors don't routinely recommend the test, partly because access to densitometers is
still not widely available. People should talk to their doctors about their risk factors
for osteoporosis and if, and when, they should get the test. Ideally, women should have
bone density measured at menopause, and periodically afterward, depending on the condition
of their bones. Men should be tested around age 65. Men and women with additional risk
factors, such as those who take certain medications, may need to be tested earlier. |
