Comparison of effective doses for low-dose MDCT and radiographic examination of sinuses in children

AJR Am J Roentgenol. 2005 May;184(5):1611-8. doi: 10.2214/ajr.184.5.01841611.


Objective: Our objective was to show that in low-dose MDCT of the sinuses in children the effective dose can be lowered to a level comparable to that used for standard radiographic images, with resultant CT scans that are still of diagnostic image quality.

Materials and methods: In standard radiographic examinations of sinuses (anteroposterior and lateral views) with 75 kV, 20 mAs, and 3-mm aluminum filtration in 69 children (mean age, 4.2 years), the dose-area-product (DAP; mGy x cm2) was measured and converted to effective dose (mSv) according to coefficients published by the British National Radiological Protection Board. Another group of 125 children (mean age, 6.8 years) underwent low-dose MDCT of the sinuses with 6- or 16-MDCT in two phases and with different scanning protocols. An effective dose for MDCT was calculated from conversion of the dose-length-product (DLP, mGy xm) according to age.

Results: The mean effective dose (E) for standard radiography was 0.0528 mSv. The mean E value for low-dose MDCT was 0.096 mSv in the first phase of the study but could be lowered in the second phase to 0.0531 mSv by a combination of higher pitch and faster scan rotation time in our scan protocols, which results in diagnostic image quality at a very low dose. Statistical analysis showed no significant differences in effective dose between radiography and MDCT of the second phase.

Conclusion: With modern MDCT technology, low-dose CT of the sinuses in children can yield diagnostic image quality using an effective dose comparable to that used for standard radiography.

Publication types

  • Comparative Study

MeSH terms

  • Adolescent
  • Child
  • Child, Preschool
  • Female
  • Humans
  • Infant
  • Male
  • Paranasal Sinus Diseases / diagnostic imaging*
  • Paranasal Sinuses / diagnostic imaging*
  • Radiation Dosage
  • Statistics, Nonparametric
  • Tomography, X-Ray Computed / methods*