From: Algorithms for joint activity–attenuation estimation from positron emission tomography scatter
N j
2×2
4×4
8×8
9×9
16×16
\(\underline {\boldsymbol {K}}\)
1.31
2.41
2.79
2.78
1.85
A λ
2.25
7.76
17.4
18.9
23.0