Various misalignment scenarios of axis shift for the tomosynthesis system with dual-axis scanning geometry.

(a) the ideal situation. (b) HF-axis shift in the HF-axis scanning direction. (c) LR-axis shift in the HF-axis scanning direction. (d) both HF-axis and LR-axis shifts in the HF-axis scanning direction. (e) HF-axis shift in the HF-axis and LR-axis scanning directions, respectively. (f) the HF axis exhibits HF-axis shift, and the LR axis exhibits LR-axis shift. (g) the HF axis exhibits LR-axis shift, and the LR axis exhibits HF-axis shift. (h) only the LR-axis position of LR-axis scanning is appropriate for the system geometry. (i) only the HF-axis position of LR-axis scanning is appropriate for the system geometry. (j) none of the axis positions are suitable for the system geometry. (k) and (i) are special cases in which the center points of the two scanning axes are the same but different from the center of the detector.