A Monte Carlo model for bone mineral measurement using dual energy X-ray absorptiometry

A detailed Monte Carlo model designed to simulate bone mineral measurements using a typical K-edge DEXA technique (LUNAR DPX-L bone densitometer) has been developed. Factors considered in the model include measurement geometry, K-edge filtration of the X-ray spectrum, photon statistics, count rate corrections and detector resolution. Two semi infinite elliptical phantoms simulating the lumbar spine and the femoral neck respectively have been used. Each phantom consists of four tissue components-fat, lean soft tissue, cortical bone and trabecular bone. Model results display similar levels of accuracy and precision to those observed in clinical practice. The Monte Carlo model of bone mineral measurements provides a valid tool for study of the LUNAR DPX-L DEXA technique.