Bone Density

A bone density test measures the strength of your bones to determine if you have osteoporosis. Osteoporosis happens when the bones lose calcium and other minerals that keep them strong.

In many women, Osteoporosis begins after menopause and gets worse after age 65. This can lead to serious bone fractures.

How it Works

Most bone density scanners use Dual Energy X-ray Absorptiometry (DEXA). The machine takes a picture of the bones in your spine, hip, body and wrist, and calculates their density. If a DEXA machine is not available, bone density scans can also be done with dual photon absorptiometry (measuring the spine, hip and total body) and quantitative computed tomography scans (measuring the spine). Some bone density scanners just use DEXA technology to measure bone density in the wrist (called pDEXA scans). These are available at some drugstores but are not as accurate as those that measure bone density in the total body, spine or hip - where most fractures occur.

During a DEXA bone density scan you lie on a bed underneath the scanner, a curving plastic arm that emits x-rays. These low-dose x-rays form a fan beam that rotates around your body. During the test, the scanner moves to capture images of your spine, hip or entire body. A computer then compares your bone strength and risk of fracture to that of other people of the same age and to young people at peak bone density. Bones reach peak density at age 30 and then start to lose mass.

The test takes about 20 minutes to do and is painless. You will only be exposed to a small amount of radiation - about one-fiftieth that of a chest x-ray, or about the amount you get during a cross-country airplane flight.

For more information about your test please visit the RadiologyInfo website.

radiology info logo

    Contact Us

  • CHA Cambridge Hospital

    1493 Cambridge St. Cambridge, MA 02139

    T - Th.: 8 am - 12 pm
    W: 8 am - 4 pm

    Schedule an Appointment
    (617) 665-1566

  • CHA Everett Hospital

    96 Garland St. Everett, MA 02149

    M / T / Th: 8 am - 4 pm

    Schedule an Appointment
    (617) 665-1298