Dual energy X-ray absorptiometry: inter-machine variability.

P A Tataranni; D J Pettitt; E Ravussin

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PubMed · 8923164

Dual energy X-ray absorptiometry: inter-machine variability.

P A Tataranni·D J Pettitt·E Ravussin

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Abstract

OBJECTIVE: Dual-energy X-ray absorptiometry (DEXA) is rapidly becoming the method of choice for body composition measurements. We tested inter-machine variability because large differences in body composition measurements between different DEXA machines have recently been reported. DESIGN: Comparison of total body scans using 2 DEXA machines from the same manufacturer (DPX-L; Lunar Co, Madison, WI) on 10 volunteers (5M/5F). RESULTS: We observed statistically significant differences between the 2 machines for all mean values of body composition variables as a result of a systematic underestimation of bone mineral and overestimation of fat tissue by one machine vs the other. However, the magnitude of the observed differences was small (namely bone mineral +68 +/- 57 g; percent body fat -1.7 +/- 1%, Mean +/- s.d.). CONCLUSION: Differences do exist in the performances of 2 DEXA machines from the same manufacturer. Although the differences reported in the present study are small, emphasis should be given in pre-testing machines when multiple apparatuses are used in a study. Also, because the observed error was systematic, randomized designs are necessary when more than one DEXA machine is used in longitudinal/intervention study. Better yet, manufacturers of DEXA machine should standardize their equipment to ensure the best consistency between machines.

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P A Tataranni, D J Pettitt, E Ravussin. 1996. Dual energy X-ray absorptiometry: inter-machine variability.. https://pubmed.ncbi.nlm.nih.gov/8923164/

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