Fig. 3From: Decoding intra-tumoral spatial heterogeneity on radiological images using the Hilbert curveTwo-dimensional Hilbert curves with level 1 (a) and level 2 (b) were, respectively, stretched into a straight line from \(P_{0}\) to \(P_{1}\). c Example of the dimensionality reduction of a three-dimensional mass with 16 voxels to a two-dimensional matrix with 4āĆā4 pixels using a three-dimensional Hilbert curveBack to article page