Skip to main content
. 2021 Dec 14;303(1):130–138. doi: 10.1148/radiol.212579

Figure 2:

Image noise was reduced by 11.5% and 34.5% for quantum iterative reconstruction (QIR, Siemens) images using strengths of 1 and 3, respectively (labeled QIR1 and QIR3), relative to weighted filtered back projection (WFBP) using Hr40 (head-regular, sharpness level 40) kernel. (A) Bar graph has horizontal dotted lines to assist the reader in comparing noise levels between the collimation settings. (B, C) Noise power spectra (NPS) curves for standard (STD) (B) and high-spatial-resolution (HR) collimations (C) demonstrate that QIR reduced noise magnitude (height of curve) compared with WFBP images for both collimations and QIR strengths without shifting spatial frequency of the peak of the noise power spectrum curves, indicating that only the amount of noise, and not noise texture, is affected with use of QIR.

Image noise was reduced by 11.5% and 34.5% for quantum iterative reconstruction (QIR, Siemens) images using strengths of 1 and 3, respectively (labeled QIR1 and QIR3), relative to weighted filtered back projection (WFBP) using Hr40 (head-regular, sharpness level 40) kernel. (A) Bar graph has horizontal dotted lines to assist the reader in comparing noise levels between the collimation settings. (B, C) Noise power spectra (NPS) curves for standard (STD) (B) and high-spatial-resolution (HR) collimations (C) demonstrate that QIR reduced noise magnitude (height of curve) compared with WFBP images for both collimations and QIR strengths without shifting spatial frequency of the peak of the noise power spectrum curves, indicating that only the amount of noise, and not noise texture, is affected with use of QIR.