title: Quality control of DXA instruments in multicenter trials.
abstract: Dual-energy X-ray absorptiometry (DXA) has become the measurement of choice for multicenter trials with bone density endpoints. When performing DXA measurements with several different systems, it is important to implement a quality assurance program to guarantee that any observed density changes are real and not due to machine and/or operator variability. In this study, we present a series of procedures based on phantom measurements designed to monitor DXA instrument stability. Techniques for longitudinal evaluation of machine performance and cross-calibration of instruments are described. These procedures are then demonstrated using quality assurance data collected from a number of different DXA scanners. Together these methods provide a defined approach to instrument quality control. Though based primarily on the use of spinal phantoms, these procedures can be generalized for use in any multicenter DXA study.
mesh_terms: D015502:Absorptiometry, Photon / Q000295:instrumentation* / Q000592:standards; D015519:Bone Density / Q000502:physiology*; D002138:Calibration; D002986:Clinical Trials as Topic; D006801:Humans; D008137:Longitudinal Studies; D015337:Multicenter Studies as Topic; D011786:Quality Control