FIGURE 5.

Rescanning strategies: (a) volumetric rescanning, (b) layered rescanning, (c) breath sampled layered rescanning, and (d) continuous breath‐sampled layered rescanning. The energy switching time, t_es , is dictated by the machine, while the time delay between the layers, ∆t, is introduced in the breath‐sampled techniques to spread the layer rescans of an energy level over the full breathing cycle (line thicknesses illustrate the relative weight of each layer). Engwall et al. Phys. Med. Biol. 2018;63: 095006. https://doi.org/10.1088/1361‐6560