Bone Mineral Density Test to Evaluate the Condition of Your Bones
A bone mineral density test measures the density of minerals in your bones using a special X-ray or computed tomography (CT) scan to calculate the strength of your bones. As we age, bones become thinner because existing bone is broken down faster than new bone is made. This unbalance results in loss of calcium and other minerals thereby making the bones lighter, less dense, and more porous. This makes the bones weaker and increases the chance of fracture.
Bone mineral density (BMD) test gives you detailed information about the condition of your bones. Given below are some of the BMD tests:
Dual-energy X-ray absorptiometry (DEXA): Two different X-ray beams are used to estimate bone density in your spine and hip. Healthy bones allow less of the X-ray beam to pass through them. It is fast, uses very low doses of radiation and is considered to be the most accurate way to measure BMD.
Peripheral dual-energy X-ray absorptiometry (P-DEXA): This test is used to measure the density of bones in the arms or legs, such as the wrist. However, it is not a suitable method to measure the density of the bones that is most likely to break, such as the hip and spine. P-DEXA uses very low doses of radiation. This method is not as useful as DEXA for evaluating how well medicine used to treat osteoporosis is working.
Dual photon absorptiometry (DPA): This test uses a radioactive substance to measure bone density in your hip and spine. DPA also uses very low doses of radiation; however, it has a slower scan time as compared to other methods.
Quantitative computed tomography (QCT): This test is conducted to measure the density of a bone in the spine. QCT is not generally used because it is expensive, uses higher radiation doses, and is less accurate as compared to DEXA, P-DEXA, or DPA.
If your bone density is lower than normal, you need to take steps to increase your bone strength by following proper diet and doing regular exercise.