Fig. 1. Schematic diagram of PTCT scanning mode

Fig. 2. Planar geometric model of PTCT

Fig. 3. Geometric model of multi-translation PTCT. (a) 4T geometric model; (b) 6T geometric model

Fig. 4. Parallel-beam geometric model of the 1T-PTCT

Fig. 5. Fan-beam geometric model of 1T-PTCT

Fig. 6. Reconstruct the geometric relationship of point M

Fig. 7. Schematic diagram of nth translation of PTCT coordinate system

Fig. 8. Reconstruction process by PTCT-DHB algorithm. (a) Original phantom image; (b) image reconstructed from the 1^st translation’s projections; (c)--(e) images reconstructed from the 1^st-2^nd,1^st-3^rd, and 1^st-4^th translations’ projections, respectively; (f) final image reconstructed from 5T projections

Fig. 9. Images reconstructed by different algorithms. (a) Original phantom image; (b)--(d) images reconstructed by PTCT-SIRT algorithm, PTCT-FBP algorithm, and PTCT-DHB algorithm, respectively; (e)--(h) magnified images of rectangle selected regions of Fig. (a)--(d), respectively

Fig. 10. Profiles along the horizontal center of images reconstructed by different algorithms

Fig. 11. Experimental system of PTCT

Fig. 12. Images reconstructed by different algorithms. (a) PTCT-SIRT algorithm; (b) PTCT-FBP algorithm; (c) PTCT-DHB algorithm; (d)--(f) magnified images of rectangle selected regions of Fig. (a)--(c), respectively

Fig. 13. Amplitude-frequency characteristics of derivation operation and backward difference operation