Calcif Tissue Int (1992) 51:449
Calcified Tissue International 9 1992 Springer-Verlag New York Inc.
Letter to the Editor
Acronyms in Bone Densitometry In response to our publication , Wilson et al.  proposed the adoption of a uniform terminology and corresponding abbreviation for dual X-ray absorptiometry (DXA). We supported this suggestion . Since then, the number of papers on DXA has increased considerably. Still, different abbreviations (DEXA, DER, DRA, QDR and DPX) for this technique for bone densitometry are used, several of which are proprietary in origin. DXA is the upgraded version of DPA (Dual Photon Absorptiometry). The nuclear source has been replaced by an X-ray source, and this improved technology has gained widespread acceptance and distribution. Recently, there have been similar developments in SPA (single photon absorptiometry) which will add yet another abbreviation to densitometry-terminology: SXA for single X-ray absorptiometry, not the alternative SEXA. Users and manufacturers of these techniques have now joined efforts in an International Standards Committee  in which standards of calibration, measurement units, and terminology are discussed. There is a general agreement that standard abbreviations for bone densitometry techniques are necessary and the term DXA has been accepted. Therefore, we would like to emphasize the use of the acronym DXA for dual X-ray absorptiometry and add the acronym SXA for single X-ray absorptiometry. When we confine ourselves to SPA, SXA, DPA, and DXA, next to QCT for quantitative computed tomography, both researchers and clinicians will understand what we mean. Still, good acronyms for ultrasound attenuation and velocity measurements and for magnetic resonance measurements, both for quantifying bone mineral density and struc-
ture, have to be agreed upon. Acronyms such as QUS for quantitative ultrasound and QMR for quantitative magnetic resonance would be consistent with QCT. Such terminology,. however, would clearly need consensus development. Harry K. Genant Claus C. Gliier Kenneth G. Faulkner Sharmila Majumdar Steve T. Harris Klaus Engelke Satoshi Hagiwaea Cornelis van Kuijk Osteoporosis Research Group Department of Radiology University of California San Francisco San Francisco, California USA References
1. G1/ierCC, Steiger P, SelvidgeR, Elliesen-Kliefoth K, Hayashi C, Genant HK (1990) Comparative assessment of dual-photon absorptiometry and dual-energy radiography. Radiology 174:223228 2. WilsonCR, Collier D, Carrera GF, Jacobson DR (1990) Acronym for dual-energy X-ray absorptiometry. Radiology 176:875 3. Gliier CC, Steiger P, Genant HK (Reply) (1990) Radiology 176:875-876 4. Nord RH, Stein JA, Mazess RB, Pommet RP (Letter) (1991) Bone Miner 13:85