DEXA Bone Densitometry
A Dual-Energy X-Ray Absorptiometry (DEXA) test is a bone density study used to determine whether or not you have osteoporosis or low bone mass, conditions that commonly affect women after menopause and, in some cases, men. It is a fast, safe, painless test that measures bone strength and can predict your risk for bone fracture. DEXA may also be used as a follow-up procedure to monitor response to specific medications.
What Are The Benefits Of DEXA?
DEXA is most often performed on the lower spine and hips. It also can measure vertebral height and assess possible vertebral fractures in the thoracic and lumbar spine. It is an advanced form of testing that is highly accurate and requires less radiation exposure than older methods of bone density testing.
What Is Involved With A DEXA Test?
The DEXA unit consists of a central device with a large flat table, and an "arm" suspended overhead. When measuring bone density in the spine, you lie on the table with your legs supported on a padded box to flatten the pelvis and spine. When measuring bone density in the hip, your foot will be placed in a brace designed to rotate your hip inward. In either case, the detector will slowly pass your body, generating images on a computer monitor.
You will be asked to lie very still and may be required to hold your breath for a few seconds to reduce the possibility of a blurred image. The test can take anywhere from 10 to 30 minutes, depending on the part of your body being imaged.
What to Expect?
- Preparation: You may be asked to wear loose, comfortable clothing without metal zippers, buttons, or accessories that could interfere with the imaging process. Sometimes, you may be asked to change into a gown. It is important to inform the technologist if you are pregnant or have recently had any imaging tests using barium or contrast agents.
- Explanation: Before the exam, the technologist will explain the procedure and answer any questions you may have. They will also ensure that you are aware of any potential risks or side effects associated with the exam.
- Positioning: You will lie flat on an exam table, usually on your back. The scanner arm will pass over your body and capture images, which typically focuses on the hip and spine but could include other sites as well.
- Minimal discomfort: The exam is generally painless and non-invasive. You may be required to hold still and may feel slight pressure on certain parts of your body as the equipment moves.
- Radiation exposure: DEXA scans involve low levels of radiation, significantly less than a standard X-ray. The potential risks associated with radiation exposure are considered minimal, but inform the technologist if you are pregnant or have concerns about radiation.
- Duration: The examination length can vary, but it usually takes around 10 to 30 minutes, depending on the number of sites being evaluated.
- Interpretation of results: After the exam, a radiologist will analyze the images and generate a report. This report will include your bone mineral density measurements and estimated risk of fractures. The results will be shared with your referring physician, who will discuss them with you during a follow-up appointment.
It is important to note that specific protocols might vary depending on the facility and the radiologist's preferences.