Skip to main content
Log in

Dose reduction by automatic exposure control in multidetector computed tomography: comparison between measurement and calculation

  • Physics
  • Published:
European Radiology Aims and scope Submit manuscript

Abstract

The aim of this study was to investigate the potential of dose reduction in multidetector computed tomography (MDCT) by current-modulated automatic exposure control (AEC) and to test the reliability of the dose estimation by the conventional CT dosimetry program CT-EXPO, when an average tube current is used. Phantom measurements were performed at a CT system with 64 detector rows for four representative examination protocols, each without and with current-modulated AEC. Organ and effective doses were measured by thermoluminescence dosimeters (TLD) at an anthropomorphic Alderson phantom and compared with those given by the calculation with CT-EXPO. The application of AEC yielded dose reductions between 27 and 40% (TLD measurements). While good linearity was observed between measured and computed effective dose values both without and with AEC, the organ doses showed large deviations between measurement and calculation. The dose to patients undergoing a MDCT examination can be reduced considerably by applying a current-modulated AEC. Dosimetric algorithms using a constant current–time product provide reliable estimates of the effective dose.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4

Similar content being viewed by others

References

  1. Amis ES Jr, Butler PF, Applegate KE, Birnbaum SB, Brateman LF, Hevezi JM, Mettler FA, Morin RL, Pentecost MJ, Smith GG, Strauss KJ, Zeman RK (2007) American College of Radiology. American College of Radiology white paper on radiation dose in medicine. J Am Coll Radiol 4:272–284

    Article  PubMed  Google Scholar 

  2. Umweltradioaktivität und Strahlenbelastung im Jahr 2006. Deutscher Bundestag Drucksache 16/6835, 2007, http://dip21.bundestag.de/dip21/btd/16/068/1606835.pdf. Accessed 15 May 2008

  3. Mettler FA (2007) Magnitude of radiation uses and doses in the United States: NCRP Scientific Committee 6-2 Analysis of Medical Exposures. In: Forty-third annual meeting of the National Council on Radiation Protection and Measurement (NCRP) Advances in radiation protection in medicine, pp 9−10

  4. Nishizawa K, Matsumoto M, Iwai K, Maruyama T (2004) Survey of CT practice in Japan and collective effective dose estimation. Nippon Acta Radiol 64:151–158

    PubMed  Google Scholar 

  5. Greess H, Wolf H, Suess C, Kalender WA, Bautz W, Baum U (2004) Dosisautomatik bei der Mehrzeilen-CT: Phantommessungen und klinische Ergebnisse. Fortschr Röntgenstr 176:862–869

    Article  CAS  Google Scholar 

  6. Graser A, Wintersperger BJ, Suess C, Reiser MF, Becker CR (2006) Dose reduction and image quality in MDCT colonography using tube current modulation. AJR:187 September 2006:695–701

  7. Russel MT, Fink JR, Rebeles F, Kanal K, Ramos M, Anzai Y (2008) Balancing radiation dose and image quality: clinical application of neck volume CT. AJNR Am J Neroradiol. doi:10.3174/ajnrA0891

  8. Kalender WA, Buchenau S, Deak P, Kellermeister M, Langner O, van Straten M, Vollmar S, Wilharm S (2008) Technical approaches to the optimisation of CT. Phys Med 24(2):71–79

    Article  PubMed  Google Scholar 

  9. Stamm G, Nagel HD (2002) CT-Expo − ein neuartiges Programm zur Dosisevaluierung in der CT. Fortschr Rontgenstr 174:1570–1576

    Article  CAS  Google Scholar 

  10. Keat N (2005) CT scanner automatic exposure control systems. MHRA Report 05016

  11. Brix G, Lechel U, Glatting G, Ziegler S, Münzing W, Müller S, Beyer T (2005) Radiation exposure of patients undergoing whole-body dual modality 18F-FDG PET/CT examinations. J Nucl Med 46:608–613

    PubMed  CAS  Google Scholar 

  12. ICRU Publication 17 (1970) Radiation dosimetry: X rays generated at potentials of 5 to 150 kV. ICRU, Washington, DC

  13. European Commission (2000) Report EUR 19604 EN: recommendations for patient dosimetry in diagnostic radiology using TLD

  14. Jastrow W (2008) Atlas of human sections in [sic] the internet. Labelling of sections from the visible human project. http://www.uni-mainz.de/FB/Medizin/Anatomie/workshop/englWelcome.html. Accessed 15 May 2008

  15. Huda W, Sandison GA (1984) Estimation of mean organ doses in diagnostic radiology from Rando phantom measurements. Health Physics 47:463–467

    PubMed  CAS  Google Scholar 

  16. ICRP Publication 60 (1991) 1990 recommendations of the International Commission on Radiological Protection. Annals of the ICRP vol 21/1-3. Elsevier Science, Oxford

  17. Taylor B, Kuyatt C (2001) Guidelines for evaluating and expressing the uncertainty of NIST measurement results. National Institute of Standards and Technology, Gaithersburg, MD. http://physics.nist.gov/Pubs/guidelines/TN1297/tn1297s.pdf. Accessed 15 May 2008

  18. Aschan C (1999) Applicability of thermoluminescent dosimeters in x-ray organ dose determination and in the dosimetry of systemic and boron neutron capture radiotherapy. University of Helsinki HU-P-D77

  19. Zankl M, Panzer W, Drexler G (1991) The calculation of dose from external photon exposures using reference human phantoms and Monte Carlo methods. Part IV. Organ doses from tomographic examinations. GSF report 30/91. Neuherberg

  20. Galanski M, Nagel HD, Stamm G (2001) CT-Expositionspraxis in der Bundesrepublik Deutschland. RoFo 173:R1–R66

    PubMed  CAS  Google Scholar 

  21. Nagel HD, Galanski M, Hidajat N, Maier W, Schmidt T (2002) Radiation exposure in computed tomography – fundamentals, influencing parameters, dose assessment, optimization, scanner data, terminology, 4th edn. CTB, Hamburg

  22. Brix G, Lechel U, Veit R, Truckenbrodt R, Stamm G, Coppenrath EM, Griebel J, Nage HD (2004) Assessment of a theoretical formalism for dose estimation in CT: an anthropomorphic phantom study. Eur Radiol 14:1275–1284

    Article  PubMed  CAS  Google Scholar 

  23. Hidajat N, Vogel T, Schröder RJ, Felix R (1996) Berechnete Organdosen und effektive Dosis für die computertomographische Untersuchung des Thorax und Abdomens: Sind diese Dosen realistisch. RoFo 164:382–387

    PubMed  CAS  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to U. Lechel.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Lechel, U., Becker, C., Langenfeld-Jäger, G. et al. Dose reduction by automatic exposure control in multidetector computed tomography: comparison between measurement and calculation. Eur Radiol 19, 1027–1034 (2009). https://doi.org/10.1007/s00330-008-1204-6

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00330-008-1204-6

Keywords

Navigation