A dual energy X-ray absorptiometry (DEXA) bone scan is a medical imaging technique used to assess the bone density of a patient. In the typical procedure, small amounts of X-ray radiation from two different sources are directed through the patient’s bones, and a detector measures the amount of radiation that isn’t absorbed by the body. The scan is most commonly employed to check for osteoporosis. Since the dose of radiation is small, there are usually no side effects.
To form an image, a DEXA bone scan uses a small dose of low energy X-rays. The radiation is sent through the body, and the amount that is blocked provides an estimation of bone density. In most cases, two different sources of radiation are used at the same time because this increases the accuracy of the scan. Once the data has been collected, it is transmitted to a computer which processes the information and determines whether the patient has a normal level of bone density.
There are a number of people who are candidates for a DEXA bone scan. It is most commonly used to detect the signs of osteoporosis, a disease that affects the bones. This condition can increase the risk of fractures. Those who have suffered bone fractures from minor falls, or have taken steroids for a long period of time, and women experiencing an early menopause are all at risk for getting osteoporosis, and may require a bone scan.
A DEXA bone scan is usually a straightforward process. Typically, the patient will lie on his or her back for about 15 minutes while the scan takes place. Clothing may need to be removed depending on which area of the body is being scanned. Injections are seldom required, and generally no patient preparation is needed. Some of the most common areas of the body to undergo a DEXA bone scan include the wrist, hip, and back bones.
In the vast majority of cases, there will be no negative side effects after a DEXA bone scan. Only a small amount of low energy radiation passes through the body, which is generally not a risk factor for healthy adults. Babies, however, may be harmed by this procedure, so pregnant women should usually avoid this type of scan. It is also important for the patient to understand that a DEXA bone scan can be a useful tool, but it only provides a limited amount of information.