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# Table 3 Linear mixed models for 1.5 T and 3 T multi-center temperature-adjusted *T*_{1} mapping data (normalized to 21 °C, considering the “Medium” native myocardium tubes “F” and “M” respectively). The best model is “A5” at 1.5 T and “A3” at 3 T

Model fitting formulas | AIC | BIC | Log likelihood | χ^{2} | valueP | Best model | ||
---|---|---|---|---|---|---|---|---|

1.5 T model | A1: T_{1} ~ sequence + (1|ID) | 5850.3 | 5920.8 | − 2909.1 | “ref” | “ref” | “ref” | |

A2: T_{1} ~ sequence + (1|ID/age) [worse fit with age] | 5852.3 | 5927.2 | − 2909.1 | 0.0 | 1.000 | – | ||

A3: T_{1} ~ sequence × software + (1|ID) | 5725.4 | 5883.9 | − 2826.7 | 164.9 | < 0.0001 | – | ||

A4: T_{1} ~ sequence × software + vendor + (1|ID) [vendor non-contributory to fit] | 5725.4 | 5883.9 | − 2826.7 | 0.0 | 1.000 | – | ||

A5: T_{1} ~ sequence × software + model + (1|ID) | 5723.4 | 5890.8 | − 2823.7 | 5.9 | 0.051 | A5 | ||

A6: T_{1} ~ sequence × software + vendor × model + (1|ID) [vendor non-contributory to fit] | 5723.4 | 5890.8 | − 2823.7 | 0.0 | 1.000 | – | ||

Final model (A5) parameters | Variance | SD | χ^{2} | Pvalue | ||||

Random effects | ID | 2547.2 | 50.47 | “ref” | “ref” | |||

Fixed effects | Sequence ( range β− 32.3 to 455.6^{a}) | / | / | 1101.0 | < 0.0001 | |||

Software ( range 385.1 to 522.3β^{a}) | / | / | 63.8 | < 0.0001 | ||||

Model ( range − 161.8 to 16.0β^{a}) | / | / | 11.2 | 0.011 | ||||

Sequence: Software ( range − 161.8 to − 6.9β^{a}) | / | / | 149.6 | < 0.0001 | ||||

3 T model | A1: T_{1} ~ sequence + (1|ID) | 4390.4 | 4447.0 | − 2181.2 | “ref” | “ref” | “ref” | |

A2: T_{1} ~ sequence + (1|ID/age) [worse fit with age] | 4392.4 | 4453.1 | − 2181.2 | 0.0 | 1.000 | – | ||

A3: T_{1} ~ sequence × software + (1|ID) | 4238.3 | 4339.4 | − 2094.2 | 174.1 | < 0.0001 | A3 | ||

A4: T_{1} ~ sequence × software + vendor + (1|ID) [vendor non-contributory to fit] | 4238.3 | 4339.4 | − 2094.2 | 0.0 | 1.000 | – | ||

A5: T_{1} ~ sequence × software + model + (1|ID) | 4239.2 | 4348.4 | − 2092.6 | 3.1 | 0.212 | – | ||

A6: T_{1} ~ sequence × software + vendor × model + (1|ID) [vendor non-contributory to fit] | 4239.2 | 4348.4 | − 2092.6 | 0.0 | 1.000 | – | ||

Final model (A3) parameters | Variance | SD | χ^{2} | P-value | ||||

Random effects | ID | 372.4 | 19.3 | “ref” | “ref” | |||

Fixed effects | Sequence ( range − 114.5 to 38.5β^{a}) | / | / | 732.8 | < 0.0001 | |||

Software ( range − 203.0 to 32.7β^{a}) | / | / | 46.0 | < 0.0001 | ||||

Sequence: Software ( range − 48.8 to 267.3β^{a}) | / | / | 189.0 | < 0.0001 |