What is the test used for?

DEXA (or DXA or osteodensitometry) is used to measure bone mineral density. The most common cause for loss of bone density is osteoporosis.

What is the preparation for the test?

There is no preparation required.

If you had had a nuclear medicine or an x-ray examination requiring barium (CT, barium meal or barium enema) in the previous 7 days you would be required to delay a week for the bone density procedure.

Will I have to undress?

You will be asked to remove most of your clothes, but may keep on your underpants. Clips, buckles, zippers etc would otherwise get in the way and cause an error in the readings. You will be asked to change into a hospital gown.

Where will I be for the test?

You will be asked to lie on a flat table, which is padded, and quite comfortable. The examination is performed with you lying on your back.

How is the test done?

A thin beam of x-ray energy is passed through the lower spine and hip regions. A computer calculates how much of x-ray energy is absorbed by the bones and compares the results with what is expected in a young (20-year-old) person, and also with what is expected for a person of your age, sex and race. In some cases a companion x-ray of your lower back from the side will be taken.

The results are plotted on a graph, and a report given by the radiologist.

How long will it all take?

15 to 20 minutes.

And after the test?

You can leave after the scan is done. If you need to wait for the results, it will take approximately 45 minutes to generate the graph and the report.

Does the test use radiation?

Low-dose ionising radiation is used.