title: Reproduction of the lumbar lordosis: a comparison of standing radiographs versus supine magnetic resonance imaging obtained with straightened lower extremities.
abstract: OBJECTIVE
  This study investigates whether it is possible to reproduce the lumbar lordosis in the upright position during magnetic resonance imaging (MRI) by positioning the patient supine with straightened lower extremities and investigates intra- and interexaminer reliability of measurements of the lumbar lordosis on radiographs and MRI.
  
  
  METHODS
  This was an observational study, which included an intra- and interexaminer reliability study. The lumbar lordosis was measured digitally on radiographs taken from 22 patients in an upright standing position, and 22 MRI scans of the same patients lying supine with straightened lower extremities. These measurements were compared statistically. Intra- and interexaminer reliability was calculated applying the Bland and Altman method.
  
  
  RESULTS
  The lumbar lordosis in the standing position was reproduced in the straightened supine position with a median deviation of 3 degrees . Intra- and interexaminer reliability was better for MRI than for radiographs. The mean differences were close to 0, especially for interexaminer reliability during MRI. On radiographs, there was a higher agreement on interexaminer than on intra-examiner reliability.
  
  
  CONCLUSIONS
  The findings of this study show that lumbar lordosis in the upright position can be reproduced by positioning the patient supine with straightened lower extremities.
authors.affiliation: Back Research Centre, Clinical Locomotion Science, Ringe, Denmark. langhoffandreasen@gmail.com
authors.forename: Marianne Løgtholt
authors.initials: ML
authors.lastname: Andreasen
authors.forename: Lotte
authors.initials: L
authors.lastname: Langhoff
authors.forename: Tue Secher
authors.initials: TS
authors.lastname: Jensen
authors.forename: Hanne B
authors.initials: HB
authors.lastname: Albert
mesh_terms: D005260:Female; D006801:Humans; D008141:Lordosis / Q000175:diagnosis* / Q000000981:diagnostic imaging; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging* / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D011187:Posture; D011237:Predictive Value of Tests; D016684:Prone Position; D011859:Radiography; D015203:Reproducibility of Results