Abstract
Dual-photon absorptiometry (DPA) is a well-established procedure for measuring bone mineral density (BMD). Recently, dual-energy X-ray absorptiomery (DXA) has become available, which has the ability to measure BMD both regionally and in the total body (TB). We have evaluated the in vivo and in vitro precision of a DXA instrument and compared it with a DPA instrument with similar software characteristics.
The short-term precision of BMD measurements using DXA was assessed in 65 postmenopausal women who had duplicate scans performed, with repositioning between scans. Precision was 0.9% in the lumbar spine and 1.4% in the femoral neck.
The midterm precision of DXA was compared with DPA by scanning 10 volunteers a mean of four times over 24 weeks, on both instruments. The precision of the bone mineral content (BMC) and area measurements was significantly better (P<0.05) with DXA than with DPA. Long-term in vitro precision was assessed by scanning an aluminium spine phantom over 42 weeks, and a cadaveric sample over 52 weeks, on both instruments. Precision was similar using the aluminium phantom, but was significantly improved (P<0.001) when using DXA for scanning the cadaveric sample.
Highly significant correlations (allP<0.001) of BMD, BMC and area measurements were observed when 70 volunteers were scanned on both instruments. However, there was a systematic difference in BMD values between the instruments. The precision of TB composition measurements assessed in 16 volunteers, over a 16-week period, were TB BMD 0.65%, TB lean tissue 1.47%, and TB fat tissue 2.73%. The correlation between weight measured by electronic scales and TB mass as measured by DXA, which was assessed in 70 volunteers, was excellent (r=0.99,p<0.001).
We conclude that DXA offers improvements in measuring BMD over DPA in terms of faster scanning times and improved resolution, resulting in better precision, with the additional advantage of the ability to measure TB composition with high precision.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Wahner HW, Dunn WL, Mazess RB et al. Dual-photon Gdl53 absorptiometry of bone. Radiology 1985; 156:203–5.
Stevenson JC, Whitehead MI. Postmenopausal osteoporosis. Br Med J 1982; 285:585–8.
Linsay R, Fey C, Haboubi A. Dual-photon absorptiometric measurements of bone mineral density increase with source life. Calcif Tissue Int 1987; 41:293–4.
DaCosta MC, Luckey MM, Meier DE, Mandeli JP, DeLaney ML, Stritze PH, Goldsmith SJ. Effect of source strength and attentuation on dual-photon absorptiometry. J Nucl Med 1989; 30:1875–81.
Stein JA, Hochberg AM, Lazewatsky L. Quantitative digital radiography for bone mineral analysis. In: Dequeker JV, Geusens P, Wahner HW, eds. Bone mineral measurements by photon absorptiometry: methodological problems. Lourain, Belgium: Leuven University Press 1987:411–14.
Mazess RB, Collick B, Trempe J, Barden H, Hanson J. Performance evaluation of a dual-energy X-ray bone densitometer. Calcif Tissue Int 1989; 44:228–32.
Gundry CR, Miller CW, Ramof E, Moscona A, Stein JA, Mazess RB, Sartoris DJ, Resnich D. Dual-energy radiographic absorptiometry of the lumbar spine: clinical experience of two systems. Radiology 1990; 174:539–41.
Pacifici R, Rupich R, Vered I, Fischer KC, Griffin M, Susman N, Avioli LV. Dual-energy radiology (DER): a preliminary comparative study. Calcif Tissue Int 1988; 43:189–91.
Wahner HW, Dunn WL, Brown ML, Morin RL, Riggs BL. Comparison of dual-energy X-ray absorptiometry and dual-photon absorptiometry for bone mineral measurements of the lumbar spine. Mayo Clin Proc 1988; 63:1075–84.
Kelly TL, Slovik DM, Schoenfeld DA, Neer RM. Quantitative digital radiography versus dual-photon absorptiometry of the lumbar spine. J Clin Endocrinol Metab 1988; 67:839–44.
Strause L, Bracker M, Saltman P, Sartoris D, Kerr E. A comparison of quantitative dual-energy radiographic absorptiometry and dual-photon absorptiometry of the lumbar spine in postmenopausal women. Calcif Tissue Int 1989; 45:288–91.
Gluer CC, Steiger P, Selvidge R, Elliesen-Klieforth K, Hayashi C, Genant HK. Comparative assessment of dual-photon absorptiometry and dual-energy radiography. Radiology 1990; 174:223–8.
Hansen MA, Hassager C, Overgaard K, Marslew U, Riis BJ, Christiansen C. Dual-energy X-ray absorptiometry: a precise method of measuring bone mineral density in the lumbar spine. J Nucl Med 1990; 31:1156–62.
Mazess RB, Barden HS, Bisek JP, Hanson J. Dual-energy X-ray absorptiometry for total body and regional bone mineral and soft tissue composition. Am J Clin Nutr 1990; 51:1106–12.
LeBlanc AD, Evans HJ, Marsh C, Schneider V, Johnson PC, Jhingran SG. Precision of dual-photon absorptiometry measurements. J Nucl Med 1986; 27:1362–5.
Stevenson JC, Lees B, Devenport M, Cust MP, Ganger KF. Determinants of bone density in normal women: risk factors for osteoporosis? Br Med J 1989; 298:924–8.
Wilson CR. Bone mineral content of the femoral neck and spine versus the radius or ulna. J Bone Joint Surg [Am] 1977; 59:665–9.
Heymsfield SB, Wang J, Kehayias JJ, Pierson RN. Dual-photon absorptiometry: comparison of bone mineral and soft tissue mass measurements in vivo with established methods. Am J Clin Nutr 1989; 49:1283–9.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Lees, B., Stevenson, J.C. An evaluation of dual-energy X-ray absorptiometry and comparison with dual-photon absorptiometry. Osteoporosis Int 2, 146–152 (1992). https://doi.org/10.1007/BF01623822
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF01623822