title: Body composition analysis by DEXA by using dynamically changing samarium filtration.
abstract: Dual-energy X-ray absorptiometry (DEXA) has a high accuracy for body composition analysis but is influenced by beam hardening and other error sources in the extremes of measurement. To compensate for beam hardening, the Norland XR-36 introduces a dynamically changing samarium filtration system, which depends on the current-absorber thickness. With this system we found a good agreement (r = 0.99) between reference and measured amounts of tissue or fat percentages in a plastic phantom and in smaller (approximately 0.5-4 kg) and larger (approximately 5-20 kg) piles of tissue (ox muscle and lard). Scans of six healthy volunteers covered with combinations of beef and lard (approximately 5-15 kg) showed a good agreement (r = 0.99) between reference and DEXA values of added soft tissue mass and fat percentage. We conclude that the DEXA method (and, in particular, the Norland XR-36 using dynamic filtration) has a high accuracy for body composition analysis. It has a potential for gaining status as a reference method in the future and may presently be used as a supplement to the traditional methods for body composition analysis.
authors.affiliation: Department of Internal Medicine, Copenhagen University Hospital, Hvidovre, Denmark.
authors.forename: A
authors.initials: A
authors.lastname: Gotfredsen
authors.forename: L
authors.initials: L
authors.lastname: Baeksgaard
authors.forename: J
authors.initials: J
authors.lastname: Hilsted
mesh_terms: D015502:Absorptiometry, Photon / Q000295:instrumentation*; D000328:Adult; D000818:Animals; D001823:Body Composition / Q000502:physiology*; D015519:Bone Density; D002417:Cattle; D005069:Evaluation Studies as Topic; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008055:Lipids / Q000737:chemistry; D008297:Male; D008953:Models, Anatomic; D018482:Muscle, Skeletal / Q000737:chemistry; D012044:Regression Analysis; D012493:Samarium
chemical_list: D008055:Lipids; D012493:Samarium