The bone mineral density (BMX) of a human body is measured by Dual-Energy X-ray Absorptiometry (DEXA). The method involves passing X-rays through bones. The denser the bone, the more it will resist the rays. This will tell the bone mineral density. This method is widely used to diagnose osteoporosis, a condition where bones tend to be very weak and brittle. It is said that the DEXA scan is better and more accurate than CT scans or regular X-rays. At Radiology Center at Harding, located at Morristown, New Jersey, the specialists in taking X-ray images are present to carry out the scan.

How is DEXA scan done?

No specific or special preparation is needed for DEXA scan. Even the clothes that you can wear during the scan depends on the area that is to be scanned. You can remain fully clothed but can't wear clothes with metal fasteners like buckles, hooks or zips. Some cases may require you to wear a gown.

Procedure

•    DEXA scan doesn't require you to have an injection or go into a tunnel. You must lie flat on your back on an open X-ray table. Make sure that you stay still during the scan so that the images are clear and not blurred.

•    The procedure of DEXA scan involves passing of a large scanning arm over the body to measure the bone density of the bones in the center of the body. The scanning arm that moves over the body actually passes X-rays. These are a narrow beam of low dose X-rays that pass through the body parts being scanned.

•    DEXA scan focuses mainly on hip and lower spine to diagnose osteoporosis. Also, bone density is not the same in all body parts. This might require more than one body part to be scanned.

•    When rays are passed through bones, some of them are absorbed by tissues like fat and bone. This is why "dual" rays are passed so that appropriate results can be found.

•    The scanning arm has an X-ray detector which measures the number of X-rays that are being passed through the body during the scan.

•    This information is essential to note in order to produce an image of the scanned area. The whole procedure takes a maximum of 15 to 20 minutes.

•    The scan of the forearm may be done if the hip or lower spine scan is not possible. Also, to diagnose hyperparathyroidism, forearm scan can be done.

Results

The results of the DEXA scan will compare your actual body density with expected body density of a healthy adult about the same age. This difference is what lets the doctor judge the condition of bone density and determine if they're weak, brittle or healthy.