Bone densitometry, also known as DEXA (dual-energy x-ray absorptiometry), is a test that uses x-ray to determine bone mineral density.
A low dose of x-rays and a computer are used to compute a "t score", the common measurement for bone density. Your t score shows the amount of bone you have compared with a young adult with peak bone mass. In many cases, bone loss can be combated with treatment and prevention, and DEXA is the current standard for bone density testing and tracking bone loss and/or retention over time.
How to Prepare for your Visit
Because calcium supplements can interfere with the accuracy of bone density testing, you are advised to stop taking calcium supplements for 24 hours prior to your exam. Please inform your technician if there is a chance you may be pregnant. The DEXA scan may not be advised for pregnant women and for patients who have recently undergone a barium exam or an imaging procedure with contrast agent. Please inform your physician or technician of any recent imaging tests you have had.
WHAT TO EXPECT
You may be asked to wear an exam gown for the test, in order to minimize interference from dense parts of clothing (belts, zippers, etc.). You will be asked to lie down on the padded exam table and bolsters may be used to achieve optimal positioning for the scan. A mechanical arm, which houses the source of the x-ray beam, will pass over your body during the exam. You will be asked to hold very still during the exam in order to achieve the most accurate reading possible. The procedure is painless and should take anywhere from 10-30 minutes depending on the number of readings taken.