Bone mineral density (BMD) testing is a widely available clinical tool for screening and diagnosing osteoporosis. These studies are also used to predict fracture risk and monitor response to therapy. Bone mineral density can be measured using different techniques in a variety of central (ie, hip or spine) or peripheral (ie, wrist, finger, heel) sites.
The following technologies are most commonly used to measure BMD.
Dual-energy X-ray Absorptiometry — (DXA) is recommended by the National Osteoporosis Foundation (NOF) for bone density test of the spine, hips and pelvis to diagnose osteoporosis. When testing can’t be done on the spine, hips and pelvis, NOF suggests a central DXA test of the radius bone in the forearm. DXA can also be used to measure peripheral sites, such as the wrist and finger. DXA is non- invasive and provides precise measurements of bone density with minimal radiation.
Quantitative Computerized Tomography — (QCT) is a type of computed tomography (CT) that provides accurate measures of bone density in the spine. Compared with DXA, QCT is less readily available and associated with relatively high radiation exposure.
Portable Peripheral Bone Density testing — portable devices that can determine BMD at peripheral sites such as the radius, phalanges, or calcaneus.
Single Photon Absorptiometry (SPA) and Dual-Photon Absorptiometry (DPA) — measure bone mineral content at the distal radius (SPA) and the spine and hip (DPA) using photons emitted at low energy levels.