Contrast-enhanced 3D micro-CT of plant tissues using different impregnation techniques

Contrast altering effects of varying concentrations of cesium iodide delivered to apple (cv. Kanzi) hypanthium. Greyscales (a–c, g–i) and segmented binary images (d–f, j–l) are sequentially of control, 1, 2.5, 5, 7.5 and 10% w/v cesium iodide embedded samples. In the control greyscale (a), intercellular air space and cells are designated by the black and dark grey pixels, respectively. Contrast embedded samples (b, c, g–i) have dark grey pixels designated as cells, while airspace can be either black or light grey pixels (where brightness of the grey is proportional to concentration of the solution). Thin light grey lines in between cells observed in g, h and i marks cell boundaries. Semi-automatic segmentation was applied to the greyscale images to yield the matching binaries (below greyscale), which attempted to assign white pixels to the cells and black pixels to the background. All scale bars present are set at 300 μ