Fig. 6From: Algorithms for joint activity–attenuation estimation from positron emission tomography scatterComparison of algorithms, with the same phantom at a human size, b rabbit size, c rat size. NMSE of ρ in the image domain as a function of iteration number for different algorithms. Left, 9×9 voxels; right, 18×18 voxels. Note the quick divergence of MLEM-OSL towards infinity at human scale; see Fig. 7a for an extended vertical plot rangeBack to article page