Improvement of image quality and dose reduction with SEMAR and AIDR 3D in paranasal sinus CT

Aims: CT is a frequently used and useful technique although it causes radiation exposure. In some situations, metal artefacts can reduce the diagnostic value of imaging. Our study aims to investigate the CT parameters for paranasal sinus imaging with less artefact and lower radiation dose at diagnostic limits, by applying SEMAR+AIDR 3D techniques together. Methods: A head-neck equivalent phantom was used to create a setup containing tissue-like densities and metal artefact at the paranasal sinus level. Then CT scans were performed with different tube voltage and current values when SEMAR+AIDR 3D techniques were off and on. Effective doses were calculated for each CT scan. Signal-to-noise ratio and contrast-to-noise ratio values were calculated for objective evaluation and image quality was assessed subjectively by two different observers blindly. Results: After tecniques, significant improvments were observed both objective and subjective values (p<0.05 and p<0.0001 respectively). 16 low-dose scans were diagnostically adequate for both observers, SEMAR+AIDR 3D was present in 15 of the 16. The lowest effective dose (0,0145 mSv) was acquired with SEMAR+AIDR 3D at 100 kVp and 3 mAs parameters. Conclusion: Image quality can be improved by using SEMAR+AIDR 3D in paranasal sinus CT, it is possible to obtain reasonable quality CT scans at head radiography effective dose values.