title: Cross-Calibration of GE Healthcare Lunar Prodigy and iDXA Dual-Energy X-Ray Densitometers for Bone Mineral Measurements.
abstract: In long-term prospective studies, dual-energy X-ray absorptiometry (DXA) devices need to be inevitably changed. It is essential to assess whether systematic differences will exist between measurements with the new and old device. A group of female volunteers (21-72 years) underwent anteroposterior lumbar spine L2-L4 (n = 72), proximal femur (n = 72), and total body (n = 62) measurements with the Prodigy and the iDXA scanners at the same visit. The bone mineral density (BMD) measurements with these two scanners showed a high linear association at all tested sites (r = 0.962-0.995; p < 0.0001). The average iDXA BMD values were 1.5%, 0.5%, and 0.9% higher than those of Prodigy for lumbar spine (L2-L4) (p < 0.0001), femoral neck (p = 0.048), and total hip (p < 0.0001), respectively. Total body BMD values measured with the iDXA were -1.3% lower (p < 0.0001) than those measured with the Prodigy. For total body, lumbar spine, and femoral neck, the BMD differences as measured with these two devices were independent of subject height and weight. Linear correction equations were developed to ensure comparability of BMD measurements obtained with both DXA scanners. Importantly, use of equations from previous studies would have increased the discrepancy between these particular DXA scanners, especially at hip and at spine.
authors.affiliation: Kuopio Musculoskeletal Research Unit (KMRU), Surgery, Institute of Clinical Medicine, University of Eastern Finland, 70211 Kuopio, Finland.
authors.forename: J
authors.initials: J
authors.lastname: Saarelainen
authors.affiliation: Department of Applied Physics, University of Eastern Finland, 70211 Kuopio, Finland; Department of Clinical Physiology and Nuclear Medicine, Kuopio University Hospital, 70029 Kuopio, Finland.
authors.forename: M
authors.initials: M
authors.lastname: Hakulinen
authors.affiliation: Kuopio Musculoskeletal Research Unit (KMRU), Surgery, Institute of Clinical Medicine, University of Eastern Finland, 70211 Kuopio, Finland.
authors.forename: T
authors.initials: T
authors.lastname: Rikkonen
authors.affiliation: Kuopio Musculoskeletal Research Unit (KMRU), Surgery, Institute of Clinical Medicine, University of Eastern Finland, 70211 Kuopio, Finland; Department of Orthopaedics, Traumatology and Hand Surgery, Kuopio University Hospital, 70029 Kuopio, Finland.
authors.forename: H
authors.initials: H
authors.lastname: Kröger
authors.affiliation: Kuopio Musculoskeletal Research Unit (KMRU), Surgery, Institute of Clinical Medicine, University of Eastern Finland, 70211 Kuopio, Finland; Department of Obstetrics and Gynaecology, Kuopio University Hospital, 70029 Kuopio, Finland.
authors.forename: M
authors.initials: M
authors.lastname: Tuppurainen
authors.affiliation: Institute of Clinical Medicine, Psychiatry, University of Eastern Finland, 70211 Kuopio, Finland; Departments of Psychiatry, Kuopio University Hospital, 70029 Kuopio, Finland; South-Savonia Hospital District, 50520 Mikkeli, Finland; North Karelia Central Hospital, 80210 Joensuu, Finland; SOSTERI, 57120 Savonlinna, Finland; SOTE, 74101 Iisalmi, Finland; Lapland Hospital District, 96101 Rovaniemi, Finland; Clinic of Child Psychiatry, University Hospital of Oulu, 90029 Oulu, Finland.
authors.forename: H
authors.initials: H
authors.lastname: Koivumaa-Honkanen
authors.affiliation: Kuopio Musculoskeletal Research Unit (KMRU), Surgery, Institute of Clinical Medicine, University of Eastern Finland, 70211 Kuopio, Finland.
authors.forename: R
authors.initials: R
authors.lastname: Honkanen
authors.affiliation: School of Computing, University of Eastern Finland, 70211 Kuopio, Finland.
authors.forename: M
authors.initials: M
authors.lastname: Hujo
authors.affiliation: Department of Applied Physics, University of Eastern Finland, 70211 Kuopio, Finland; Diagnostic Imaging Centre, Kuopio University Hospital, 70029 Kuopio, Finland.
authors.forename: J S
authors.initials: JS
authors.lastname: Jurvelin