Bones are a part of the body that are responsible for ensuring that we don’t end up falling to a blob like mass due the force of gravity. Bones are the foundations upon which the entire body is held together. Years of evolution have gone behind the creation of this form of tissue, and the end result is that it is a hardened matrix like structure made up of calcium and phosphorus. The inner most section is called the bone marrow, which is responsible for the creation of red and white blood cells in the body. Just like any other tissue, even bone is subject to disease. Osteoporosis is one such disease, in which bones become brittle. This is the main measurement taken by a bone density test. Other tests conducted include a bone scan for arthritis, bone scan images for minute fractures, and a radioactive bone scan for infections like osteomyelitis.
Bone mineral density measurement is a metric that is used to find out how thick a bone is. The main disease that brittle bones are associated with is osteoporosis. This is a degenerative disease that women after menopause or low estrogen levels are especially prone to. Estrogen controls the amount of calcium in the body and the lesser the amount of this hormone, the lesser the amount of calcium to create bone tissue. The result being that the bone withers away and the patient ends up being more susceptible to fractures.
There is no specific preparation that needs to be done for a bone scan. Some bone scans that are done using nuclear medicine’s scanning techniques would require that you ingest some radioactive material before the test. Since this material accumulates in the urine, it is necessary that you empty your bladder just before the test.
One of the most popular methods of testing bone density is a Dual energy X ray Absorptiometry or DXA. Since there is some debate on using area instead of volume in the calculation of density, the results are usually confirmed using a variant of the CT scan. The ideal bone density measurement is represented as a score like T-score -1.0, which is the normal score though higher values are considered normal as well. A reading between -1 and -2.5 is considered to be a condition that is a precursor to osteoporosis called osteopenia. Higher than -2.5 is a case of osteoporosis