The DEXA Scan

DEXA or DXA stands for “Dual Energy X-ray Absorptiometry,” which is a type of bone density technology. The DEXA machine takes a picture of your bones and calculates their density. Physicians commonly choose DEXA because it uses a low level of radiation (about the same as you would get on a flight from New York to Los Angeles), but detects low levels of bone loss much better than a simple X-ray. After your first scan, you should get one every one to two years to measure changes in your bone density.

DEXA scans come in two types, the p-DEXA and the central DEXA:

 p-DEXA

  • The “p” stands for “peripheral.” This scan measures bones on the body’s periphery—meaning areas away from the center of the body—such as the heel, wrist, or finger.
  • This type of bone density test is often offered at malls and health fairs. However, p-DEXA results should not be used for diagnosis or tracking progress from year to year. These tests are good screening tools and can indicate whether or not you are at high risk and should get a central DEXA scan.

Central DEXA

  • The central DEXA measures bone density in the center of the body—in the spine and hip. People are most likely to experience low bone density in these areas, and they are where low bone density is most dangerous and debilitating.
  • These scans can provide an accurate diagnosis and method of tracking your progress from year to year.