What is a DEXA scan?
A DEXA scan or Dual Energy X-ray Absortiometry is the most popular method available to measure the density of bone mineral. During the test the patient has to lie down on a padded examination table while the scanner directs x-ray energy rapidly from two different sources. This energy is directed in an alternating manner towards the bones being examined at a frequency that is set. The patient’s mineral density causes the transmission of these two x-ray sources to weaken or prolong through a filter onto a counter, depending on the quantity of bone mass that is present. The greater the density of bone mineral, the greater would be the signals that the photon counter picks up. What is a DEXA scan used for and what are its benefits? As mentioned earlier, a DEXA scan is used to measure the density of bone mineral. This method is highly advantageous as it is very precise and helps measure small changes that take place in bone mass. This is quite a flexible test and can be used to measure the spine along with the extremities. The scan does not take too much time and one can get a scan of the spine in one minute, the hip in two minutes, and the entire body in about four minutes. DEXA scanning is not as expensive as compared to other tests and does not expose the patient to excessive radiation. The test is also known to be extremely accurate at recording subtle changes that take place in bone density over a period of time. How do the results of a DEXA scan help patients? People with osteoporosis have bone density that is substantially lower as compared to normal people their age. Bone mineral density indicates the strength of your bones. By comparing your values to standard measurements that are there for bone density, it is possible to predict your chances for getting a fracture from any minor trauma. Things to keep in mind before a DEXA scan : It is important that you wear loose clothing for the test and are as comfortable as possible. Clothes that have metal buttons and zippers are an absolute no-no. Make sure you do not take any calcium supplements at least 48 hours before a DEXA scan. Remind your radiologist about any back or hip surgery that you may have undergone. It is advisable that you avoid this test if you think you might be pregnant or are pregnant.
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