The clinical investigator

, Volume 71, Issue 8, pp 600–603

Overestimation of osteopenia using standard analysis software for peripheral quantitative computed tomography

  • R. Lehmann
  • H. M. Kvasnicka
  • M. Wapniarz
  • K. Klein
  • B. Allolio
Original Article

DOI: 10.1007/BF00184482

Cite this article as:
Lehmann, R., Kvasnicka, H.M., Wapniarz, M. et al. Clin Investig (1993) 71: 600. doi:10.1007/BF00184482

Summary

It is well established that measurement of bone mineral density (BMD) can estimate the risk of future fractures. To assess individual fracture risk BMD measurements are compared with a reference range provided by the manufacturer of the respective BMD technology. However, the power of trabecular bone measured by peripheral quantitative computed tomography (pQCT) to predict future fractures has not been shown up to now. We conducted measurements of trabecular bone density (TBD) at the distal radius (pQCT XCT 900, Stratec, Germany) in a sample of 506 healthy white women aged 40–60 years (mean 48) and compared the results with the manufacturer's normal range. We found a remarkable difference in TBD values between our healthy study population and the manufacturer's reference data in all age groups (e.g., age 50–54 years, 143.1 ± 43.2 mg/cm3 versus 181.1 ± 39.0 mg/cm3). Compared to the ± 2 SD limits of the manufacturer's reference range our study population showed mean TBD values that were about 1 SD below the mean of the reference range. About 50% of our healthy cohort were below the −1 SD limit of the reference range. Almost ten times as many normal subjects as expected (22.1%) were found below the −2 SD limit and therefore classified as individuals with increased fracture risk. This overestimation of fracture risk leads to discomfort of the patient, unnecessary therapeutic intervention, and significant costs to the public. This difference is probably due to the fact that the manufacturer's reference values were generated with the older device (SCT 900) using a 125I source, and that these were later used in devices with an X-ray source. Correction of the manufacturer's software is now underway; all devices with X-ray source distributed in Germany by the company must receive a new software with a generally agreed reference data-set. Our study indicates that a reliable reference database must become a prerequisite for the approvement of BMD technology prior to the use in patients.

Key words

Peripheral quantitative computed tomographyTrabecular bone densityReference values

Abbreviations

pQCT

peripheral quantitative computed tomography

TBD

trabecular bone density

BMD

bone mineral density

Copyright information

© Springer-Verlag 1993

Authors and Affiliations

  • R. Lehmann
    • 1
  • H. M. Kvasnicka
    • 2
  • M. Wapniarz
    • 1
  • K. Klein
    • 3
  • B. Allolio
    • 1
  1. 1.Medizinische KlinikUniversität WürzburgWürburgGermany
  2. 2.Institut für PathologieUniversität KölnKölnGermany
  3. 3.Erziehungswissenschaftliche FakultätUniversität KölnKölnGermany