Fig. 6.

Evaluation of compaction (measured on the x-axis: from 0 to 200; 1 unit = 3 µm; axial position or depth) and brightness (backscattered intensity) (y-axis from 0 to 800 AU (arbitral units). Compaction of epidermis: (Δ_EP = distance from first peak to the valley’s middle point in µm) and brightness of epidermis (I _EP = difference between first peak and the 200 AU line: under this value only noise could be detected on the original DICOM image). Compaction of DEJ (Δ_DEJ = angle (in degrees) produced by the descendent line of the valley and the ascendant line of the valley) and brightness of DEJ (I _DEJ = difference between the bottom of the valley and the 200 AU line). Compaction of PD (Δ_PD = distance from middle of valley to second peak in µm) and brightness of PD (I _PD = difference between the highest peak after the valley and the 200 AU line). The highest peak after the valley represents the junction between PD and RD [33]). Depth of visibility of fibers in RD (V _RD in µm): under the 200 AU line only noise could be detected. a Compaction and brightness in young-aged skin (for discussion see “Results”). b Compaction and brightness in middle-aged skin (for discussion see “Results”). c Compaction and brightness in old aged skin (for discussion see “Results”)