Figure 8.

Examples of an imperfect deformation vector field (DVF). A, An axial slice of the Z-displacement (superior–inferior [SI]) in millimeters at the end of inhalation (EOI) phase. The blue arrow indicates some scattered “holes” in the smooth region. B, A sagittal slice of the EOI phase volume showing bone/muscle connectivity. C, A sagittal slice of aliasing EOI phase volume when bony structures in category IV are modeled in the same way as category III in the end of exhalation (EOE) phase volume only. Red circles indicate the aliased spine and cortical bone caused by the DVF discontinuity.