Figure 5

Effects of compression ratio on the center and peripheral thicknesses of PTA slices. Thicknesses of 12 slices obtained from various radial positions of a PTA segment are shown at a compression ratio of 0% (a). Similarly, thicknesses of seven slices obtained from another PTA segment are shown at a compression ratio of 40% (b). The relationship between the relative thickness at the center and the compression ratio is shown in (c). In panels (a) and (b), thicknesses were measured along a length of 1 mm (364 pixels) and averaged. Since no systematic changes were found in the radial direction, all samples obtained in various radial positions were cumulated in panel (c).