A bone density scan can detect thinning bones at an early stage, osteoporosis or osteopenia. If you already have osteoporosis, bone scans can also tell you how fast the disease is progressing. The most common test for tracking bone density over time is the DXA (dual-energy X-ray absorptiometry) scan. A DXA (sometimes pronounced “dexa”) scan is fast, accurate, pain-free, and has very low radiation.
Dual energy X-ray absorptiometry, or DEXA, is the most common method to measure a patient’s BMD. There are small DEXA scanners called peripheral DEXA machines. These machines often measure BMD at the heel (calcaneus), shin bone (distal tibia), middle finger, or kneecap (patella). Regular DEXA machines have a standard reference (called NHANES III) that can be used for all machines, no matter the manufacturer.