title: Comparative study of the density of L2, L3, and L4 vertebrae in menopausal women aged over 50 years with osteoporosis.
abstract: BACKGROUND
  The Index used for osteoporosis detection was BMD measured in L2, L3, and L4 vertebrae. We compared the density of the vertebrae to select the one with maximum change in the density for decreasing the cost and the time.
  
  
  METHODS
  Ninety seven osteoporotic post-menopausal women with a mean age of 61.78 ± 8.48 (50 - 86) years and a mean body mass index (BMI) of 24.75 ± 2.66 (kg/m(2)) (18 - 30) without any known diseases and on any medication affecting bone mineral density (BMD) were examined at osteoporosis section of a teaching hospital. The vertebral bodies (L2 - L4) of participants were measured by using a dual energy X-ray absorptiometry system (DEXA). To investigate if the BMD measurement of a single vertebra could replace the total L2 - L4 measurement, the mean BMDs and the correlations of the L2 - L4 were compared.
  
  
  RESULTS
  Among the 97 studied women, the mean BMI was 24.75 ± 2.66. The mean BMD of L2, L3, and L4 vertebrae were 0.7199, 0.7258, and 0.7402, respectively. There was no significant difference between the mean BMD of L2 and L3 vertebrae (P > 0.05), suggesting a strong relationship between L2 and L3. The mean BMD in the L4 vertebra was significantly higher than the other two vertebrae (P < 0.05), Statistical analysis showed that the BMD in all three L2, L3, and L4 vertebrae were associated with BMI (r > 0 and P < 0.05), but there was no significant relationship between BMD and age in the three L2, L3, and L4 vertebrae (r ≅ 0 and P > 0.05).
  
  
  CONCLUSIONS
  Since the mean BMDs of L2 and L3 were not significantly different, and due to a very high correlation between L2 and L3, we recommend the measurement of L2 rather than L2 - L4 in order to save patient scanning time, cost, and the patient X-ray exposure.
authors.affiliation: Department of Medical Physics and Biomedical Engineering, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Mohammad Bagher
authors.initials: MB
authors.lastname: Tavakoli
authors.affiliation: Department of Medical Physics and Biomedical Engineering, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Salamat
authors.affiliation: Department of Medical Physics and Biomedical Engineering, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Marzieh
authors.initials: M
authors.lastname: Tavakoli
keywords: Bone mineral density test; dual energy X-ray absorptiometry (DEXA); menopause; osteoporosis; quantitative computed tomography