What is dual energy x-ray absorptiometry (DEXA)?
DEXA, also known as DXA or bone density exam, uses a very small dose of x-rays to measure density of bones. These measurements are compared to normal values for patients of similar sex and age in order to assess whether or not there has been excessive bone loss or osteoporosis. This can predict a person’s risk of developing fractures. DEXA is also used to follow patients who are taking medication for osteoporosis in order to assess the effectiveness of the treatment(s).
DEXA is painless and requires no special preparation. You should let your technologist know if you are pregnant. You should also inform your technologist if you have had a recent barium exam, CT exam with contrast, or a nuclear medicine exam. You should also not take any calcium supplements for 24 hours prior to the examination.
How is a DEXA Performed?
You will be positioned on a table and very low-dose x-rays taken of specific regions of your body. The exam itself is quick and painless. The test uses x-rays of different energies to calculate the density of your bones, typically of both the hip and the spine.
You should wear loose and comfortable clothing to your examination avoiding items with zippers, belts, or other metallic objects. You may be asked to remove jewelry or other metallic objects that could interfere with the test.