Improved digital chest tomosynthesis image quality by use of a projection-based dual-energy virtual monochromatic convolutional neural network with super resolution
Fig 9
Comparisons among the Dual-Energy (DE) Virtual Monochromatic (VM) with Very-Deep Super-Resolution (VDSR) reconstruction algorithm (DE–VM–VDSR) with and without BF and conventional reconstruction algorithms [DE–VM–VDSR with and without BF (showing window: 0–0.23), FBP (kernel: Ramp; 0–0.4), SART (120 kV; 0–0.02), SART–TV–FISTA (120 kV; 0–0.4), and DE–VM–SART–TV–FISTA (60 keV; 0–0.23)] in the in-focus plane.
The window of the chest phantom N1 with lung field was varied to compare the contrast and background gray levels. For each corresponding set, the VM (DE–VM–VDSR and DE–VM–SART–TV–FISTA) images are displayed at the same window width and level, whereas the polychromatic FBP and IR images have larger window widths because the backgrounds are less flattened. The X-ray source is moved vertically along the image. Abbreviations: FBP = filtered backprojection, SART = simultaneous algebraic reconstruction technique, TV–FISTA = total-variation first-iterative shrinkage–thresholding algorithm, IR = iterative reconstruction, BF = bilateral filtering.
