Osteoporosis International

, Volume 11, Issue 10, pp 889–896

Quantitative Computed Tomography in the Evaluation of Spinal Osteoporosis Following Spinal Cord Injury

Authors

  • C. C. Liu
    • Department of Radiology, University of California San Diego and Veterans Affairs Medical Center, San Diego
  • D. J. Theodorou
    • Department of Radiology, University of California San Diego and Veterans Affairs Medical Center, San Diego
  • S. J. Theodorou
    • Department of Radiology, University of California San Diego and Veterans Affairs Medical Center, San Diego
  • M. P. Andre
    • Department of Radiology, University of California San Diego and Veterans Affairs Medical Center, San Diego
  • D. J. Sartoris
    • Department of Radiology, University of California San Diego and Veterans Affairs Medical Center, San Diego
  • S. M. Szollar
    • Department of Orthopedic Rehabilitation, University of California San Diego and Veterans Affairs Medical Center, San Diego;
  • E. M.  Martin
    • Department of Radiology, University of California San Diego and Veterans Affairs Medical Center, San Diego
  • L. J. Deftos
    • Department of Medicine and Division of Endocrinology, University of California San Diego and Veterans Affairs Medical Center, San Diego, California, USA
Original Article

DOI: 10.1007/s001980070049

Cite this article as:
Liu, C., Theodorou, D., Theodorou, S. et al. Osteoporos Int (2000) 11: 889. doi:10.1007/s001980070049

Abstract:

Disuse osteoporosis occurs in the lower extremities of patients with spinal cord injury (SCI). However, spinal osteoporosis is not usually observed in these patients. We investigated lumbar spine bone mineral density (BMD) in SCI patients using single energy quantitative computed tomography (QCT) and dual-energy X-ray absorptiometry (DXA). Our study population consisted of 64 patients with long-standing SCI. Spine BMD (g/cm3) was assessed by QCT at four vertebrae ranging from T11 to L4 with single midvertebral CT slices 1 cm thick parallel to the vertebral end-plates. Confounding variables affecting normal trabecular bone pattern, such as compression fractures, surgical hardware or fat replacement, were excluded. For a subset of 29 patients, DXA values of the spine and femoral neck were also measured, and QCT and DXA Z-scores were compared On the average, the 64 SCI patients had Z-scores 2.0 ± 1.2 below those of age-matched controls. In the subset of 29 patients with both QCT and DXA measurements, the QCT and DXA Z-scores were 2.4 ± 1.1 below and 1.3 ± 2.3 above the mean, respectively (p<0.0001). Our results indicate that QCT reveals osteoporosis of the spine after SCI, in contrast to DXA. We postulate that QCT is more valuable for evaluating spinal osteoporosis following SCI than DXA and thus recommend QCT for spinal BMD studies in SCI.

Key words:Bone disease – Disuse osteoporosis – Dual-energy X-ray absorptiometry – Imaging – Single-energy quantitative computed tomography – Spinal cord injury

Copyright information

© International Osteoporosis Foundation and National Osteoporosis Foundation 2000