Peripheral measurement techniques for the assessment of osteoporosis.

Peripheral measurement techniques have been the first to be developed for the assessment of osteoporosis, and they remain useful. Besides traditional approaches such as radiographic absorptiometry (RA), radiogrammetry, and single-photon absorptiometry (SPA), new peripheral approaches have been developed that offer powerful ways to assess skeletal status in osteoporosis. These include single x-ray absorptiometry (SXA), peripheral dual x-ray absorptiometry (pDXA), peripheral quantitative computed tomography (pQCT), quantitative ultrasound (QUS) techniques, and magnetic resonance imaging (MRI) approaches. This review describes the current role of peripheral imaging techniques vis-à-vis their central imaging counterparts. Peripheral measurement techniques are attractive because equipment cost is substantially lower, radiation exposure is small, and the devices require less space and sometimes are even portable. Additionally, QUS and MRI offer the potential to measure aspects of bone status beyond the limits of bone densitometry. Peripheral techniques represent important diagnostic methods for the assessment of osteoporosis.