This Article  • References  • Full text PDF  • Send to a friend  • Save in My Folder  • Save to citation manager  • Permissions  Citing Articles  • Contact me when this article is cited  Related Content  • Similar articles in JAMA  Social Bookmarking   What's this?

Peter Schneider, MD; Christoph Reiners, MD
University of Würzburg Würzburg, Germany

JAMA. 1997;277(1):23-24.

	Since this article does not have an abstract, we have provided the first 150 words of the full text PDF and any section headings.

To the Editor.

—Although Dr Klesges and colleagues¹ carefully assessed standardization and quality control of the dualenergy x-ray absorptiometry (DEXA) equipment used for the estimation of BMC and body composition, there is reasonable doubt that the changes in BMC they described are valid findings. It seems to be a treacherous coincidence that body calcium excretion with or without calcium supplementation impacts directly on the bone mineral status for the following reasons.

All DEXA inherently uses 2 radiation energies to resolve equations comprising at least 3 unknown variables: the attenuation coefficients of fat, water, and bone mineral. Fat and water have considerably different attenuation coefficients at low energies. In common experimental settings, such as crosscalibration efforts with invariable anthropomorphic phantoms, certain systematic errors are not detectable.² The influence of fat distribution on bone mass measurements with DEXA can be of considerable magnitude and ranges up to

Influence of simulated nonhomogeneous fat and . . . [Full Text PDF of this Article]

CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter     What's this?