Copyright © 2012
Oregon Osteoporosis Center
All rights reserved
Bone Density Testing
• Registration forms and patient questionnaire for new and returning patients If you did not already receive this material in the mail, please complete this packet and bring it with you to your appointment. You will need to call (503) 215-6586 for a login and password to allow you access to the file. (Opens in a new window; requires PDF viewing software such as Adobe Acrobat reader or Foxit Reader)
• Referral slip. This patient referral form is provided for the use and convenience of physicians and their office personnel only. The slip contains all the necessary information to refer a patient for bone density testing at the OOC.
Bone Densitometry Exam
Bone density testing is performed by a simple,
painless procedure called DXA (dual energy x-ray absorptiometry). In this
test, a weak x-ray beam is passed through the bone in the spine, hip or other
skeletal site. The amount of x-ray that passes through is measured, and provides
a very accurate determination of the calcium content of the bone. Bone density
measurement can determine the presence and the severity of osteoporosis and
can be used to predict the future risk of developing osteoporosis and fractures.
Bone density results are usually expressed as 'T-scores,' which are derived
from comparisons to values seen in young normal adults. Healthy young women
have bone density T-score values between -2 and +2. Postmenopausal women with
values between -1 and -2.5 are said to have low bone density. Low bone density
values do not necessarily mean that bone loss has occurred. They may be the
result of a lower-than-average peak bone density, perhaps due to genetic inheritance.
Values less than -2.5 are associated with an increased fracture risk, and
at this level the diagnosis of osteoporosis is made. We can also compare a
bone density result with the values we expect in other women of the same age.
Because of the bone loss seen with growing older, women over age 75 often
have osteoporosis (T-score less than -2.5) despite the fact that their values
are within the range expected for their age. Bone density testing can also
be used to monitor the effects of medical problems on bone health or of treatment
for osteoporosis. The effectiveness of treatment is best monitored by measuring
bone density when treatment begins and again after one or two years of therapy.
Things to know before your test
What is the DXA procedure like?
Bone densitometry using DXA involves lying on a padded surface with a pillow under your head. For the hip scan, legs are extended with the feet held in a positioning block. For the lower spine scan, legs are elevated on a cushion. Each scan takes five to ten minutes. There is no discomfort, and there are no injections or special dyes.
What should I do before the test?
• You will receive a medical history questionnaire in the mail prior to your exam. Bring the completed form to your appointment. If there are any questions you are unable to answer, please leave them blank and the technologist will review the questions with you. The questionnaire is used to determine any risks you may have for developing osteoporosis.
• There is no need to disrobe if you wear clothes without buttons, zippers, or plastic closures. We suggest a warm-up suit or shorts or pants with an elastic waistband.
• You should not have this exam within two weeks after a radioactive bone scan study or within one month after any kind of barium x-ray.
• Do not take any calcium or vitamin supplements the day of the exam.
• Important: If your weight is over 265 lbs., please call us prior to your exam.
How and when will I get the results?
The results of the exam will be interpreted by a physician who specializes in osteoporosis. A report of the lab tests will be sent to your physician. If you do not have your results within two weeks, call your doctor's office.
Comparing Current to Previous Bone Density Tests
One of the important uses of bone densitometry by DXA is to monitor changes in bone density over time. If you have had a previous study in our laboratory, we will automatically make a comparison with your previous results.
Comparing bone density results between different DXA bone density machines is a more difficult challenge. If you have had a previous hip or spine bone density test by DXA and would like us to attempt to compare your current test with previous results, you must provide us with copies of the following:
· Printouts of the actual hip and spine bone
· The physician's interpretation of those results
You can obtain copies of these results from your previous bone density laboratory. It would be most efficient if you bring that information with you at the time of your test. Alternatively, you can arrange for your previous bone density laboratory to mail those results directly to us as follows:
Bone Density Records
Oregon Osteoporosis Center
5050 N.E. Hoyt, Suite 626
Portland, Oregon 97213
Bone density can be measured by other techniques including by CAT scan of the spine or with other types of bone density tests of the heel, finger or forearm. Comparisons cannot be made between DXA bone density values of the spine or hip and any of these other tests.
Copyright ©2012 Oregon Osteoporosis Center. All rights reserved.