Dose and noise in abdominal computed tomography examinations

Background: Dose reduction in computed tomography (CT) examinations was an idea of the Co-rdinated Research Project (CRP) "Dose Reduction in Computed Tomography (CT) while maintaining Diagnostic Confidence", supported by the International Agency of Atomic Energy (IAEA) in the years 2003-2005. Participation in the CRP inspired the authors' attempts to elaborate a method for optimization of CT abdominal procedures allowing reduce a dose to patient with saving diagnostically satisfying image quality. The paper presents the algorithm together with clinical verification of the results of the study. Material/Methods: Two types of single-slice CT scanners were used for the investigations. The images recorded for patients undergoing routine abdomen examinations and then these obtained with modified exposure parameters were analyzed. The influence of the changed tube outputs on image quality was checked using Catphan 424 phantom. Results: As the result no statistically significant difference between the measured noise in clinical images for patients examined at routine and modified settings (within the same weight category) was observed. Conclusions: The conclusion was that at routine (screening) abdomen examinations, the dose may be reduced up to 50% with saving diagnostically satisfying image quality