Bone Density (DEXA) Dual energy
x-ray absorptiometry is a quick, painless procedure for measuring bone loss associated
with osteoporosis—a disease where decreasing bone density makes bones brittle
and prone to fracture. DEXA uses very low dose x-rays to evaluate bone status
and predict fracture risk before osteoporosis develops, allowing prevention therapy
to be started.
Bone density testing is also used to determine if particular medications
are needed to improve bone density or to evaluate the effectiveness of current
medication. Since osteoporosis usually has no warning signs or symptoms, men
and woman both should consider having a bone density test around age 35. This
provides an objective baseline against which future bone status can be compared.
Note:
DEXA exams can be done on a walk-in basis at our centers. However, you must not
have taken calcium supplements within the last 8 hours or had an imaging study
involving a contrast agent within the last 4 days. (See Preparation below for
details.)
DEXA Exam Guidelines
Preparation
- Prior to your scheduled appointment, WIS will call you to discuss specific
instructions, review your health and insurance information and answer any
questions.
- For your convenience, print out and complete the appropriate Patient
Forms,
including Patient Registration and Patient History. Bring them with you to
your appointment.
- Do not take calcium supplements 8 hours prior to your exam or on the day
of your scan.
- Leave your valuables at home. All jewelry and any metal objects must be
removed prior to the exam.
- Wear comfortable clothing without metal hooks, buttons or zippers. Pants
with an elastic waistband are recommended.
- Please notify the technologist if you are pregnant or could be pregnant.
- Let us know if there is any metal in the part of the body being imaged,
such as spinal fusion rods or a hip prosthesis.
- DEXA studies cannot be scheduled within 4 days following any contrast study
such as nuclear medicine, barium enema, UGI, IVP, etc.
- Please arrive 15 minutes prior to your exam.
What to Expect
During the Exam
- Allow approximately 15 to 30 minutes for the procedure.
- You will be asked to lie on your back on a padded scanning bed
and breathe normally. A scanner will pass over one area of your
skeleton—your lower spine or hip—as a dual energy
beam of low dose x-ray passes through your body and is measured
by a detector. You will not feel anything during the exam.
- The technologist will reposition your arms and legs as needed,
and a scan of a second skeletal area will be taken.
- DEXA technology measures the amount of x-rays absorbed by the
bones in your body. The two x-ray energies allow the machine to
differentiate between bone and soft tissue, giving a very accurate
estimation of bone density.
What to Expect After the Exam
- You may leave
as soon as the exam is completed.
- Your referring physician will receive a report and pictures
detailing the findings of your exam within 48 hours. You should
contact your doctor to discuss the results.
For more information on DEXA, check out the
Frequently
Asked Questions (FAQs) page on this modality.
