Table 4 Estimated values of the reconstructed ion concentration and the diagonal components of the conductivity tensor measured within the ROIs using the regularization parameters λ _cond and λ _opt , respectively.

λ _cond

η [S · sec/mm³]

0.80 ± 0.14

0.90 ± 0.15

0.76 ± 0.07

0.56 ± 0.06

0.32 ± 0.04

0.61 ± 0.05

0.43 ± 0.01

0.36 ± 0.02

C₁₁ [S/m]

0.27 ± 0.07

1.43 ± 0.49

0.46 ± 0.04

0.54 ± 0.04

0.44 ± 0.06

0.59 ± 0.07

1.18 ± 0.02

1.07 ± 0.05

C₂₂ [S/m]

0.93 ± 0.14

0.48 ± 0.14

0.85 ± 0.03

0.55 ± 0.06

0.44 ± 0.06

0.60 ± 0.07

1.30 ± 0.06

1.10 ± 0.06

C₃₃ [S/m]

0.41 ± 0.11

0.74 ± 0.08

0.55 ± 0.04

0.57 ± 0.05

0.45 ± 0.05

0.61 ± 0.08

1.29 ± 0.06

1.07 ± 0.06

λ _opt

η [S · sec/mm³]

0.84 ± 0.10

0.86 ± 0.08

0.65 ± 0.03

0.62 ± 0.05

0.46 ± 0.04

0.61 ± 0.03

0.50 ± 0.01

0.54 ± 0.02

C₁₁ [S/m]

0.29 ± 0.09

1.36 ± 0.37

0.40 ± 0.03

0.60 ± 0.07

0.63 ± 0.06

0.59 ± 0.09

1.39 ± 0.03

1.62 ± 0.06

C₂₂ [S/m]

0.97 ± 0.12

0.46 ± 0.10

0.73 ± 0.05

0.61 ± 0.09

0.63 ± 0.07

0.60 ± 0.09

1.53 ± 0.06

1.67 ± 0.06

C₃₃ [S/m]

0.44 ± 0.13

0.72 ± 0.09

0.48 ± 0.04

0.63 ± 0.08

0.64 ± 0.05

0.62 ± 0.09

1.52 ± 0.06

1.63 ± 0.08