What is a DEXA scan? A DEXA scan uses x-rays to measure bone density. There are two types of DEXA machines: the central DEXA devices is a larger machine that measures bones located in the center of the body, hips and the spine. Peripheral DEXA devices are smaller portable machines used to measure bone density in the wrist, heels, and fingers.
How A DEXA Scan Works
The machine works by sending low energy X-rays through the bones. They come from two sources so that the doctor can view denser bones more accurately. The rays are measured by a device called a detector. This information is calculated by a computer that figures out the density of the bones. A low score means that the bone density is weak and some mass has been lost. Bones that lose density are more likely to break or fracture. Rays used in the test are high and low.
What Happens During the Test?
The scan takes about 10 to 20 minutes. It is safe and there is no pain involved. You lie on a table while the doctor passes the machine or scanner over your body. Before the test, you can eat normally, but it is recommended that you refrain from taking any calcium supplements within the 24 hour period before the exam Avoid clothing with metal zippers and remove keys and jewelry before the scan. You will be asked to remove your clothing and wear a gown.
When the spine is tested the legs are supported by a box on the table that flattens the pelvis and lowers the spine. To check the hips the doctor often put the patient's foot in a metal brace that rotates the hip inward. The best way to take the test is to lie as still as possible.
The scanner produces two x-rays one low and the other high. It is scored using a T-score that compares your bones to a healthy 30-year-old woman. T-scores of 1.0 or higher are normal, scores of 1.5 to 2.5 are considered low, and 2.5 or higher means the person has osteoporosis. A Z-score is used to compare your score to a person in your age group and gender.
When Would I Need A DEXA Scan?
This test is normally conducted on women after menopause, individuals with arthritis and those who take medications that may cause bone loss. A person with a history of fractures, diabetes, a thyroid condition, and back pain may also be a good candidate for this test.
Avoid lifestyle choices that add to thinning bones are such as: drinking too much, smoking, lack of exercise, and diets low in calcium, phosphorus, and Vitamin D. After the test your physician may prescribe medication or recommend that you take a calcium and Vitamin D supplement.
Speak with your physician if you have an increased risk of osteoporosis. For all your imaging needs, Advanced Imaging Centers provides DEXA scans. You can schedule an appointment at one of our three centers online today!