Fig. 6
From: Decoding intra-tumoral spatial heterogeneity on radiological images using the Hilbert curve
a A Hilbert volume consisting of four blocks of VA1, VA2, VA3, and VA4 was expanded into a Hilbert matrix (b). The corresponding expansions of the four blocks were MB1, MB2, MB3, and MB4 on the matrix, respectively. c The Hilbert volume with the lung tumor inside was expanded to a two-dimensional Hilbert matrix (d). Accordingly, the voxels of the lung tumor (c) in blue were expanded into the pixels of the matrix (d) in blue