title: Result of Proficiency Test and Comparison of Accuracy Using a European Spine Phantom among the Three Bone Densitometries.
abstract: BACKGROUND
  Although dual energy X-ray absorptiometry (DXA) is known to standard equipment for bone mineral density (BMD) measurements. Different results of BMD measurement using a number of different types of devices are difficult to use clinical practice. The purpose of this study was to evaluate discrepancy and standardizations of DXA devices from three manufactures using a European Spine Phantom (ESP).
  
  
  METHODS
  We calculated the accuracy and precision of 36 DXA devices from three manufacturers (10 Hologic, 16 Lunar, and 10 Osteosys) using a ESP (semi-anthropomorphic). The ESP was measured 5 times on each equipment without repositioning. Accuracy was assessed by comparing BMD (g/cm(2)) values measured on each device with the actual value of the phantom. Precision was assessed by the coefficient of variation (CVsd).
  
  
  RESULTS
  Lunar devices were, on average, 22%, 8.3%, and 5% overestimation for low (L1) BMD values, medium (L2), and high (L3) BMD values. Hologic devices were, on average, 6% overestimation for L1 BMD, and 5% and 6.2% underestimation for L2 and L3 BMD values. Osteosys devices was, on average, 12.7% (0.063 g/cm(2)), 6.3% (0.062 g/cm(2)), and 5% (0.075 g/cm(2)) underestimation for L1, L2, and L3, respectively. The mean CVsd for L1-L3 BMD were 0.01%, 0.78%, and 2.46% for Lunar, Hologic, and Osteosys devices respectively.
  
  
  CONCLUSIONS
  The BMD comparison in this study demonstrates that BMD result of three different devices are significant different between three devices. Differences of BMD between three devices are necessary to BMD standardization.
authors.affiliation: Department of Laboratory Medicine, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Ae Ja
authors.initials: AJ
authors.lastname: Park
authors.affiliation: Department of Laboratory Medicine, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Jee-Hye
authors.initials: JH
authors.lastname: Choi
authors.affiliation: Department of Anesthesiology, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Hyun
authors.initials: H
authors.lastname: Kang
authors.affiliation: Department of Radiology, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Ki Jeong
authors.initials: KJ
authors.lastname: Park
authors.affiliation: Division of Endocrinology and Metabolism, Sanbon Medical Center, University of Wonkwang College of Medicine, Iksan, Korea.
authors.forename: Ha Young
authors.initials: HY
authors.lastname: Kim
authors.affiliation: Division of Endocrinology and Metabolism, Sanbon Medical Center, University of Wonkwang College of Medicine, Iksan, Korea.
authors.forename: Seo Hwa
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Department of Nuclear Medicine, College of Medicine, Kyung Hee University, Seoul, Korea.
authors.forename: Deog-Yoon
authors.initials: DY
authors.lastname: Kim
authors.affiliation: Department of Orthopedic Surgery, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Seung-Hwan
authors.initials: SH
authors.lastname: Park
authors.affiliation: Department of Orthopedic Surgery, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Yong-Chan
authors.initials: YC
authors.lastname: Ha
keywords: Bone density; Densitometry; Lumbar vertebrae; Reference standards