Patient Info by Procedure
Bone Densitometry (DEXA)
A bone mineral density test measures the thickness of your bones. It compares your bone measurements to two standards, known as "age matched" (your Z-score) and "young normal" (your T-score). The age-matched reading compares your bone density to what is expected in someone of your age, sex and size. The young normal reading compares your density to the optimal peak bone density of a 30 year old healthy adult of the same sex. The information is used in making a diagnosis about your bone status and fracture risk.
Bone densitometry involves a very small dose of radiation, much less than the radiation dosage of a chest x-ray. The test is painless and noninvasive.
A bone density test can detect osteoporosis before a fracture occurs and predict your chances of fractures in the future.
What should I do to prepare for the exam?
Wear loose, comfortable clothing without snaps, zippers or any metal decoration, as these objects interfere with the scan. You may be asked to change into a patient gown for the exam.
Refrain from taking any calcium eight hours before your exam.
How much time should I allow?
The exam takes less than half an hour depending on the area being tested. The spine, hip and wrist are the most commonsites of fractures due to osteoporosis.
What can I expect?
You will be asked to lie on a table while a scanning machine with a movable arm passes over the area being tested.
After the exam, you may return to your normal activity.