Kefeng Zhou, Presenter: Nothing to Disclose

Xiaoyan Xin MPH, Abstract Co-Author: Nothing to Disclose

Xiao Zhu Lin BA, Abstract Co-Author: Nothing to Disclose

Yun Shen PhD, Abstract Co-Author: Employee, General Electric Company Researcher, General Electric Company

Hua Xu MMED, Abstract Co-Author: Nothing to Disclose

Bin Zhu MD, PhD, Abstract Co-Author: Nothing to Disclose

Junkun Chen, Abstract Co-Author: Nothing to Disclose

To compare the noise reduction effect of gemstone CT with adaptive statistical iterative reconstruction (ASIR) technology at different settings of noise index.

A catphan 600 phantom was scanned on gemstone CT (Discovery HD 750, GE) at different settings of noise index (5, 10, 15, 20, 25, 30, 35, 40) Reconstruction was performed with different weightings of ASIR (0,10,20,30,40,50,60,70,80,90,100). CT values (mean±standard deviation, HU) were measured from the same ROI at the same level with different noise index and ASIR weightings. Standard deviation was taken as the noise value. Noise reduction was calculated with reference to noise value when ASIR weighting was zero. Correlation and regression analysis between noise reduction and ASIR weighting was performed by SPSS 14.0 software. CT values at different settings of noise index and ASIR weighting were compared with double-factor variance analysis.

At the same noise index, noise values decreased and noise reduction increased as ASIR weighting increased. At different settings of noise index, coefficients (55.546~57.668) and constants (1.876~2.260) of the eight linear regression equations between noise reduction and ASIR weighting changed within a quite narrow range. Hence, one integrated linear regression equation could be established: Noise reduction (%) = ±56.748*ASIR weighting + 2.127 (p<0.001). No significant differences of CT values could be found among different settings of ASIR weighting with double-factor variance analysis (F=0.236, p=0.992). However, CT values changed significantly at different settings of noise index (F=279.829, p<0.001).

Noise reduction can be achieved by ASIR technology without impairment of CT value measurement.

Noise of the images could be reduced and the radiation dose of the patients adopted could be decreased with the adaptive statistical iterative reconstruction technology.

Zhou, K, Xin, X, Lin, X, Shen, Y, Xu, H, Zhu, B, Chen, J, Comparison of Noise Reduction Effect with Adaptive Statistical Iterative Reconstruction (ASIR) at Different Settings of Noise Index: A Phantom Study.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11034238.html