This technique uses low-dose X-rays to measure the density of bone. The test is carried out to screen for and diagnose osteoporosis, a condition that is particularly common in postmenopausal women. The varying absorption of X-rays as they pass through the body is interpreted by a computer and displayed as an image. The computer calculates the average density of the bone and compares it with the normal range for the person’s age and sex. The procedure takes about 10–20 minutes and is painless.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.