Osteoporosis International

, Volume 2, Issue 2, pp 82–87

Effective dose values in bone mineral measurements by photon absorptiometry and computed tomography

  • W. A. Kalender
Original Article


A high degree of uncertainty and irritation predominates in the assessment and comparison of radiation dose values resulting from measurements of bone mineral density of the lumbar spine by photon absorptiometry and X-ray computed tomography. The skin dose values which are usually given in the literature are of limited relevance because the size of the irradiated volumes, the relative sensitivity of the affected organs and the radiation energies are not taken into account. The concept of effective dose, sometimes called whole-body equivalent dose, has to be applied. A detailed analysis results in an effective dose value of about 1 µSv for absorptiometry and about 30 µSv for computed tomography when low kV and mAs values are used. Lateral localizer radiographs, which are necessary for slice selection in CT, mean an additional dose of 30 µSv. Lateral X-ray films of the spine which are frequently taken in combination with absorptiometry result in a dose of 700 µSv or more. The concept of effective dose, the basic data and assumptions used in its assessment and a comparison with other dose burdens (for example the natural background radiation, of typically 2400 µSv per year) are discussed in detail.


Bone mineral density Dual-energy X-ray absorptiometry Computed tomography Radiation dose 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Genant HK, Block JE, Steiger P et al. Appropriate use of bone densitometry. Radiology 1989; 170: 817–22.Google Scholar
  2. 2.
    Proceedings of the 8th International Workshop on Bone Densitometry. Osteoporosis Int 1991; 1: 189–213.Google Scholar
  3. 3.
    Glüer CC, Steiger P, Genant HK. Validity of dual-photon absorptiometry. Radiology 1988; 166: 574–5.Google Scholar
  4. 4.
    Ross PD, Wasnich RD, Vogel JM. Precision error in dual-photon absorptiometry related to source age. Radiology 1988; 166: 523–7.Google Scholar
  5. 5.
    Cullum ID, Ell PJ, Ryder JP. X-ray dual-photon absorptiometry: a new method for the measurement of bone density. Brit J Radiol 1989; 62: 587–92.Google Scholar
  6. 6.
    Stein JA, Waltham MA, Lazewatsdy IL et al. Dual-energy X-ray bone densitometer incorporating an internal reference system. Radiology 1987; 165(P): 313.Google Scholar
  7. 7.
    Kalender WA, Brestowsky H, Felsenberg D. Automated determination of the midvertebral slice for CT bone mineral measurements. Radiology 1987; 168: 219–21.Google Scholar
  8. 8.
    Kalender WA, Klotz E, Süss C. Vertebral bone mineral analysis: an integrated approach with CT. Radiology 1987; 164: 419–23.Google Scholar
  9. 9.
    Cann CE. Low-dose CT scanning for quantitative spinal mineral analysis. Radiology 1981; 140: 813–15.Google Scholar
  10. 10.
    Felsenberg D, Kalender WA, Trinkwalter W et al. CT-Untersuchungen mit reduzierter Strahlendosis. Fortschr Röntgenstr 1990; 153: 516–21.Google Scholar
  11. 11.
    ICRP publication no. 33. Protection against ionizing radiation from external sources used in medicine. Frankfurt: Pergamon Press, 1982.Google Scholar
  12. 12.
    Schmidt T. Effektive Dosis — Beruflich strahlenexponierte Personen — Arztliche Überwachung (Neue Röntgenverordnung). Rntgen-Bl. 1988; 41: 444–6.Google Scholar
  13. 13.
    Traut H. Die effektive Äquivalentdosis: Erläuterungen und Anmerkungen zu einem neuen Dosiskonzept. Fortschr Röntgenstr 1989; 151: 487–90.Google Scholar
  14. 14.
    Huda W, Bissessur K. Effective dose equivalents, HE, in diagnostic radiology. Med Phys 1990; 17: 998–1003.Google Scholar
  15. 15.
    Pye DW, Hannan WJ, Hesp R. Correspondence: Effective dose equivalent in dual X-ray absorptiometry. Br J Radiol 1990; 63: 149.Google Scholar
  16. 16.
    Shope T, Gagne RM, Johnson GC. A method for describing the doses delivered by transmission X-ray computed tomography. Med Phys 1981; 8: 488–95.Google Scholar
  17. 17.
    Drexler G, Panzer W, Widenmann L et al. Die Bestimmung von Organdosen in der Röntgendiagnostik. Berlin: Hoffmann Verlag, 1985.Google Scholar
  18. 18.
    McCrohan JL, Patterson JF, Gagne RM. Average radiation doses in a standard head examination for 250 CT systems. Radiology 1987; 163: 263–8.Google Scholar
  19. 19.
    SOMATOM Plus dose and imaging performance information. Erlangen: Siemens AG Medizinische Technik. Order no. Cl-, 1990.Google Scholar
  20. 20.
    Vogel H. Strahlendosis und Strahlenrisiko in der bildgebenden Diagnostik. Landsberg: Ecomed Verlag, 1989.Google Scholar
  21. 21.
    Richardson RB. Past and revised risk for cancer induced by irradiation and their influence on dose limits. Br J Radiol 1990; 63: 235–45.Google Scholar
  22. 22.
    Unweltbericht 1990. Salzgitter: Bundesamt für Strahlenschutz, 1990.Google Scholar
  23. 23.
    Steinbach WR, Richter K, Uhlich F et al. Strahlenbelastung und-risiko von Patienten und Untersuchern bei Angiokardiographie und Koronarangiographie. Electromedica 1990; 58: 66–9.Google Scholar
  24. 24.
    Consensus development conference: Prophylaxis and treatment of osteoporosis. Conference report. Osteoporosis Int 1991; 1: 114–17.Google Scholar
  25. 25.
    Virtama P. Uneven distribution of bone minerals and covering effect of nonmineralized tissue as reasons for impaired detectability of bone density from roentgenograms. Ann Med Intern Fenn 1960; 49: 57–65.Google Scholar

Copyright information

© European Foundation for Osteoporosis 1992

Authors and Affiliations

  • W. A. Kalender
    • 1
  1. 1.Siemens AG Medizinische TechnikErlangenGermany

Personalised recommendations