Effectiveness of noise reduction with adaptive statistical iterative reconstruction in different noise index groups

Objective To compare the noise reduction effect of gemstone CT with adaptive statistical iterative reconstruction (ASIR) technology in different noise index groups.Methods A catphan 600 phantom was scanned on gemstone CT in different noise index groups(5,10,15,20,25,30,35,40).Reconstruction was performed with different weightings of ASIR(0%-100%,step 10%).CT values were measured from the same ROI.Correlation and regression analysises between noise reduction and ASIR weighting were performed by SPSS 14.0 software.CT values in different noise index groups and ASIR weighting were compared with double-factor variance analysis.Results Noise values decreased and noise reduction increased as ASIR weighting increased,which had a linear regression relationship between noise reduction and ASIR weighting.Double-factor variance analysis showed that there were no significant differences in CT values among different settings of ASIR weighting(P0.05).Conclusion Noise reduction can be achieved by ASIR technology without impairment of CT value measurement.