Tom Hendrik Mulkens MD, Presenter: Nothing to Disclose

Christel Broers MD, Abstract Co-Author: Nothing to Disclose

Steffen Fieuws MD, Abstract Co-Author: Nothing to Disclose

Patrick Bellnick MD, Abstract Co-Author: Nothing to Disclose

Jean-Luc Termote MD, Abstract Co-Author: Nothing to Disclose

We lowered the radiation dose in low dose multislice CT (MSCT) of the sinuses in children with the resultant CT scans being still of diagnostic image quality, and calculated the effective dose (E). We compared the effective dose of MSCT with the effective dose of X-ray examinations in children.

In standard X-ray examinations with 75 kV and 2 mm Al filtration of sinuses (n=51) or skull (n=18)with AP and lateral view in 69 children (mean age: 4,2 years) the total Dose-Area-Product (DAP, mGy.cm²) was measured and converted to effective dose (mSv) according to coefficients published by the British National Radiological Protection Board. Another group of 112 children (mean age: 7 years) underwent low dose MSCT of sinuses with six-slice or sixteen-slice MSCT in two phases, with different scan protocols. Effective dose for MSCT was calculated from conversion of Dose Length Product (DLP, mGy.cm), according to age.

Mean effective dose for X-ray was 0.053 mSv. Mean effective dose for low dose MSCT was 0.096 mSv in the first phase of the study (n=62), but could be lowered in the second phase down to 0.054 mSv (n=50)by a combination of higher pitch factor and faster scan rotation time in our scan protocols, which give diagnostic image quality at very low dose. Statistical analysis with Wilcoxon rank tests showed no significant difference in effective dose between X-ray and MSCT of the second phase.

With modern multislice CT technology, low dose CT of sinuses in children can be performed with comparable effective dose as standard X-ray, with diagnostic image quality.

Mulkens, T, Broers, C, Fieuws, S, Bellnick, P, Termote, J, Comparison of Effective Dose of Low Dose Multislice CT and X-ray Examination of Sinuses in Children.  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4404697.html