Table 5.
PDX Cohort MRI-Determined Parameter Test–Retest Within-Subject Variability
| Parameter | Mean Δa | SDWS Δa | Mean ΔDWb | SDWS ΔDWb | CVWS Δa (%) | CVWS ΔDWb (%) |
|---|---|---|---|---|---|---|
| Volume, μL | 1.7 | 1.5 | – | – | 0.94 | – |
| T1<ROI>, s | 0.24 | 0.21 | – | – | 11 | – |
| T1<Voxel>, s | 0.18 | 0.16 | 0.06 | 0.05 | 8.6 | 22 |
| T2<ROI>, ms | 1.8 | 1.6 | – | – | 2.6 | – |
| T2<Voxel>, ms | 1.8 | 1.6 | 1.7 | 1.6 | 2.5 | 20 |
| ADC<ROI>, μm2/ms | 0.05 | 0.05 | – | – | 7.0 | – |
| ADC<Voxel>, μm2/ms | 0.05 | 0.04 | 0.03 | 0.03 | 5.8 | 16 |
| DCE-AUC<ROI>, au | 0.17 | 0.17 | – | – | 29 | – |
| DCE-AUC<Voxel>, au | 0.17 | 0.17 | 0.15 | 0.11 | 29 | 33 |
| DCE-Ktrans<ROI>, min−1 | 0.012 | 0.013 | – | – | 32 | – |
| DCE-Ktrans<Voxel>, min−1 | 0.017 | 0.016 | 0.012 | 0.01 | 44 | 28 |
aThe symbol Δ indicates the absolute value of the difference between two paired repeat determinations.
bThe width of each voxel-wise parameter distribution is summarized as the SD of the parameter distribution. In this case, Δ for the distribution width test-retest is indicated as ΔDW.