Bone density or BMD (bone mineral density) is the amount of mineral found in the bone tissues. From the physics point of view, it describes the mineral mass as per bone’s volume. Upon imaging, the BMD is clinically measured according to an estimated optical density per square centimeter of bone’s surface. 

BMD and bone calcium are measured with the help of a scan, known as the DEXA scan which is a type of low-dose x-ray test. This low-dosage x-ray is often performed in the radiology or nuclear medicine departments. It is a non-invasive and painless procedure that encompasses low radiation exposure.

DEXA is used to diagnose osteopenia (low bone mass) that can lead to a riskier condition called osteoporosis. As a progressive disease, it turns the bone brittle and thin. This test also helps predict the risk of future fractures. It can also determine whether the treatment is successful or not.