title: Dual-energy X-ray absorptiometry versus single photon absorptiometry of the radius.
abstract: Radial diaphyseal bone mineral density (BMD) was measured at the standard one-third site by dual-energy X-ray absorptiometry (DEXA) and by 125I single photon absorptiometry (SPA) in 70 consecutive subjects, aged 12-86 years, with metabolic disorders of the skeleton. Each patient was measured once by the DEXA (Hologic QDR-1000) instrument and four times by the SPA (Norland 2780) instrument on the same day by one or the other of 2 technicians. The DEXA and SPA measurements were linearly related and highly correlated (r = 0.975, P less than 0.0001) over a range from severe osteopenia to high normal BMD. Ninety-five percent of the variation in the BMD determined by SPA was accounted for by DEXA, so that the BMD(SPA) = 1.035 +/- 0.027 (SEM) x BMD(DEXA)-0.007 +/- 0.019 (SEM). This permits continued use of previously accumulated SPA data-bases. The coefficient of variation for repeat measurements by DEXA was 1.2% and by SPA 1.6%. Examination time by DEXA was 6-7 minutes, about 45% shorter than the corresponding SPA determinations. DEXA is the superior method for evaluation of the radius, as it provides faster and more precise measurements in clinical practice.
authors.affiliation: Medical College of Georgia, Department of Medicine, Augusta 30912.
authors.forename: R S
authors.initials: RS
authors.lastname: Weinstein
authors.forename: K D
authors.initials: KD
authors.lastname: New
authors.forename: L J
authors.initials: LJ
authors.lastname: Sappington
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density; D001851:Bone Diseases, Metabolic / Q000503:physiopathology*; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011884:Radius; D012044:Regression Analysis