title: Four commonly used dual-energy X-ray absorptiometry scanners do not identically classify subjects for osteopenia or osteoporosis by T-score in four bone regions BIz11.5.
abstract: We investigated whether four commonly used dual-energy X-ray absorptiometry (DXA) scanners (DPX, DPX-L,and Prodigy by GE Lunar, and Delphi-A by Hologic) could classify identical subjects as osteopenic or osteoporotic using the T-score for bone mineral density in four regions of interest: PA spine (L1-L4), femur (total), forearm (total),and 33% radius in 77 adults (38 females) free of treatment for bone metabolic disease (age range 20-81 yr). There were no significant differences between T-score means for posterior-anterior spine by DPX, DPX-L, and Prodigy, but they were higher than the mean T-score by Delphi-A (p < 0.05). Prodigy gave the lowest and DPX and Delphi-A gave the highest T-score for 33% radius (p < 0.05). No subject was classified as osteoporotic in the femur region by the four scanners, although other classifications varied by region and scanner. No two scanners classified subjects identically for osteopenia in any of the four regions. These results indicate that classification of bone density in individual subjects using T-scores varies by different DXA scanners, even the scanners were made by the same manufacturer.
authors.affiliation: Body Composition Unit, Obesity Research Center, St. Luke's-Roosevelt Hospital-Columbia University, New York, NY 10025, USA. jw9@columbia.edu
authors.forename: Jack
authors.initials: J
authors.lastname: Wang
authors.forename: John C
authors.initials: JC
authors.lastname: Thornton
authors.forename: Elli
authors.initials: E
authors.lastname: Ioannidou
authors.forename: Janet-Mae
authors.initials: JM
authors.lastname: Soriano
authors.forename: Dympna
authors.initials: D
authors.lastname: Gallagher
authors.forename: Steven B
authors.initials: SB
authors.lastname: Heymsfield
authors.forename: Mary
authors.initials: M
authors.lastname: Horlick
authors.forename: Richard N
authors.initials: RN
authors.lastname: Pierson
authors.forename: Lynn R
authors.initials: LR
authors.lastname: Allen
mesh_terms: D015502:Absorptiometry, Photon / Q000295:instrumentation*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D015519:Bone Density; D001851:Bone Diseases, Metabolic / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000000981:diagnostic imaging*