A bone density scan, also known as a dual-energy X-ray absorptiometry (DXA or DEXA) scan, is a non-invasive test that measures the density of bones. It is commonly used to diagnose osteoporosis, a condition in which bones become brittle and weak, making them more susceptible to fractures. By measuring bone density, a DEXA scan can detect low bone density, which is a sign of osteoporosis, at an early stage, when treatment is most effective.
In addition to osteoporosis, a DEXA scan can also help diagnose other conditions that affect bone density, such as osteopenia (a milder form of bone loss) and Paget's disease of the bone (a disorder that causes abnormal bone growth and weakening).
The process of a bone density scan consists of lying on a padded table while a machine called a densitometer scans one or more areas of the body, typically the hip, spine, or forearm. The densitometer uses two low-dose X-ray beams to measure the comparable density of bones. The process is quick, non-invasive, and painless. The entire scan typically takes only about 10 to 20 minutes to complete.
During the scan, it is crucial to remain still to ensure accurate results. After the scan is complete, the results are typically given as a T-score, which compares bone density to that of a normal, healthy young adult of the patient's gender. A T-score of -1 or above is considered normal, while a T-score between -1 and -2.5 indicates low bone density (osteopenia), and a T-score of -2.5 or below indicates osteoporosis.
Why are DEXA scans important?
Osteoporosis is a big cause of concern for the older population. Particularly, the risk of fractures associated with osteoporosis increases with age, and women are at higher risk than men. Other risk factors include a family history of osteoporosis, low body weight, a sedentary lifestyle, smoking, and excessive alcohol consumption. Fractures associated with osteoporosis can have serious consequences, especially in older adults. Hip fractures, for example, can lead to prolonged hospitalization, decreased mobility, loss of independence, and an increased risk of complications such as blood clots, infections, and death.
It's important to note that not all fractures associated with osteoporosis are symptomatic. Some fractures may go unnoticed or be mistaken for other conditions, such as back pain or arthritis. Therefore, it's important for people at risk of osteoporosis to undergo regular bone density screenings and to take steps to prevent or manage the condition if diagnosed. This may include lifestyle modifications, such as regular exercise and a healthy diet, as well as medication to improve bone density and reduce fracture risk.