Estimate of FDG Excretion by means of Compartmental Analysis and Ant Colony Optimization of Nuclear Medicine Data

Table 1

Simulated values of tracer coefficients providing different cases for the matrix 𝐀; reconstructed average values and standard deviations over 30 runs of ACO (same random initialization guess) and over 30 runs of LM (30 different random initializations). Values under 10⁻³ are set to 0.

	𝑘𝑏𝑡	𝑘𝑡𝑝	𝑘𝑝𝑡	𝑘𝑢𝑝	𝑘𝑡𝑏	𝑘𝑝𝑏
𝐀 full
g. t.	1	0.02	0.02	0.08	0.3	0.3
ACO	1.01±0.11	0.02±0.01	0.02±0.01	0.08±0.01	0.32±0.03	0.31±0.02
LM	1.13±1.04	0.02±0.06	0.03±0.05	0.08±0.04	0.28±0.29	0.31±0.26
𝐀 u. t.
g. t.	0.8	0	0.02	0.1	0.4	0.2
ACO	0.88±0.10	0±0	0.02±0.01	0.11±0.01	0.41±0.05	0.20±0.02
LM	0.92±0.71	0±0	0.06±0.05	0.16±0.22	0.39±0.25	0.19±0.11
𝐀 l. t.
g. t.	0.6	0.03	0	0.1	0.35	0.35
ACO	0.59±0.05	0.03±0.01	0±0	0.10±0.01	0.35±0.02	0.35±0.02
LM	0.64±0.33	0.06±0.08	0±0	0.09±0.12	0.36±0.17	0.39±0.21
𝐀 diag.
g. t.	0.7	0	0	0.2	0.2	0.4
ACO	0.71±0.03	0±0	0±0	0.21±0.01	0.20±0.01	0.41±0.03
LM	0.74±0.36	0±0	0±0	0.17±0.11	0.25±0.12	0.46±0.31

In the first columns: g. t. stands for ground truth, u. t. for upper triangular, l. t. for lower triangular, and diag. for diagonal.