Ces radiol. 2011, 65(3):177-182

Comparison of the filtered back projection reconstruction algorithm and the iterative reconstruction algorithm (IRIS)Original article

Petra Kozubíková¹, Martin Horák²

¹ Oddělení lékařské fyziky Nemocnice Na Homolce, Praha

² Radiodiagnostické oddělení Nemocnice Na Homolce, Praha

Aim: The aim of this study was to assess the possibilities of IRIS (Iterative reconstruction in Image Space) algorithm in noise reduction and potential dose reduction.

Method: A total of 85 patients clinically underwent CT examination (chest, abdomen, brain) with IRIS reconstruction and similar groups of 95 patients with Filtered Back Projection (FBP) reconstruction were evaluated. The reference tube current product in original CT protocols was modified for IRIS algorithm according to the subjective image quality. Two reconstruction algorithms were compared in terms of image noise, signal to noise ratio and effective dose.

Results: It was demonstrated that with the novel approach the mean effective dose reduction up to 50% for CT examination of the abdomen did not lead to image quality degradation. However, to retain the quality of CT images of the brain it was accomplished mean effective dose reduction only of 23%.

Conclusion: For this reason such measurements and similar optimization should precede to introduction of any new reconstruction algorithm into clinical routine.

Keywords: FBP, IRIS, iterative reconstruction, filtered back projection, CT, effective dose

Accepted: July 15, 2011; Published: September 1, 2011  Show citation