What is considered the best test for measuring bone density?

The DEXA scan, or dual-energy X-ray absorptiometry, is recognized as the gold standard for measuring bone density. This test provides a clear and precise measurement of bone mineral density (BMD), which is crucial for diagnosing conditions like osteoporosis.

The DEXA scan uses two X-ray beams with different energy levels to assess bone density in the spine, hip, and sometimes the wrist. Its high sensitivity and specificity allow it to detect subtle changes in bone density over time, making it an invaluable tool for monitoring bone health in individuals at risk of fractures.

Other imaging modalities mentioned serve different purposes or have limitations when it comes to assessing bone density. For example, a CT scan can measure bone density but is not typically used for this purpose due to higher radiation exposure and cost. While X-rays can identify fractures and changes in bone structure, they are not sensitive enough to detect early changes in bone density. Lastly, ultrasound can assess bone quality but does not provide a direct measurement of bone density in the way that a DEXA scan does. Thus, the DEXA scan stands out as the most effective method for bone density measurement.