title: Vertebral morphometry by X-ray absorptiometry: which reference data for vertebral heights?
abstract: BACKGROUND
  The recent improvement in the resolution of dual-energy X-ray absorptiometry (DXA) images enables most vertebral levels to be seen adequately and thus DXA may be a worthwhile alternative to radiologic morphometry for the identification of vertebral fractures (VF). In this multicenter study, we have derived reference data for vertebral heights and their ratios in Italian women using morphometric X-ray absorptiometry (MXA).
  
  
  METHODS
  DXA scans were acquired in 1254 consecutive pre- and postmenopausal women, (mean age 63.7 ± 11.3, range 26-88 yrs), referred to six osteoporosis centers. MXA analysis of these images was performed by the same operator measuring vertebral heights and height ratios from L4 to T4. We calculated measures of central tendency and dispersion of vertebral heights and vertebral ratios using different approaches (mean and standard deviation as well as median and interquartile range of raw data, mean and standard deviation of trimmed data using an iterative algorithm, and mean and standard deviation of not fractured vertebrae).
  
  
  RESULTS
  Independently of the approach that we used, all the measures of central tendency were similar, while significant differences were found when compared with reference ranges in other populations. The vertebral heights of our sample at every vertebral level were significantly smaller than both Rea population and the Lunar reference values, even after normalization. Splitting data according to age groups, there was a decrease in the vertebral heights and ratios between the younger and older women.
  
  
  CONCLUSIONS
  This study demonstrates that reference data for MXA should be population specific and age matched.
authors.affiliation: Department of Radiology, Sapienza University of Rome, Italy. daniele.diacinti@uniroma1.it
authors.forename: Daniele
authors.initials: D
authors.lastname: Diacinti
authors.forename: Daniela
authors.initials: D
authors.lastname: Pisani
authors.forename: Romano
authors.initials: R
authors.lastname: Del Fiacco
authors.forename: Cristiano Maria
authors.initials: CM
authors.lastname: Francucci
authors.forename: Carmelo Erio
authors.initials: CE
authors.lastname: Fiore
authors.forename: Bruno
authors.initials: B
authors.lastname: Frediani
authors.forename: Antonella
authors.initials: A
authors.lastname: Barone
authors.forename: Tommaso
authors.initials: T
authors.lastname: Bartalena
authors.forename: Maria Sofia
authors.initials: MS
authors.lastname: Cattaruzza
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Guglielmi
authors.forename: Davide
authors.initials: D
authors.lastname: Diacinti
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Romagnoli
authors.forename: Salvatore
authors.initials: S
authors.lastname: Minisola
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods / Q000592:standards*; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D008875:Middle Aged; D000091402:Prohibitins; D012016:Reference Values; D015203:Reproducibility of Results; D016103:Spinal Fractures / Q000175:diagnosis / Q000000981:diagnostic imaging*; D013904:Thoracic Vertebrae / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*