Table 2.
Percentage of features out of the original number of features with significantly (p < 0.05) different distributions attributable to batch effects in the original features and after applying standard ComBat, OPNested ComBat, OPNested + GMM ComBat, and OPNested – ComBat. Order indicates order of batch effects used in sequential harmonization for multiple batch effects. GMM groupings are generated by selecting the best model out of a set of GMMs estimated from each feature, thus GMM feature indicates the feature corresponding to the best model used to generate the final GMM grouping for all features.
| CE | Spatial Resolution | Manufacturer | GMM Class | |
|---|---|---|---|---|
| Lung3/CAPTKa | ||||
| Original | 22.5% | 27.5% | 56.9% | 92.2% |
| ComBat | 15.7% | 16.7% | 47.1% | |
| OPNested | 4.9% | 10.8% | 31.4% | |
| OPNested + GMM | 1% | 6.9% | 4.9% | 42.2% |
| OPNested − GMM | 12.7% | 17.6% | 50% | 85.3% |
| Lung3/PyRadiomicsb | ||||
| Original | 41.9% | 51.2% | 65.1% | 84.7% |
| ComBat | 51.2% | 24.7% | 27.7% | |
| OPNested | 1.4% | 28.8% | 26.5% | |
| OPNested + GMM | 0.2% | 21.6% | 22.6% | 25.1% |
| OPNested − GMM | 4.7% | 20% | 42.8% | 76.3% |
| Radiogenomics/CAPTKc | ||||
| Original | 31.4% | 52.9% | 20.6% | 85.3% |
| ComBat | 38.2% | 40.2% | 50% | |
| OPNested | 13.7% | 21.6% | 56.9% | |
| OPNested + GMM | 8.8% | 16.7% | 11.8% | 43.1% |
| OPNested − GMM | 15.7% | 31.4% | 53.9% | 81.4% |
| Radiogenomics/PyRadiomicsd | ||||
| Original | 57.7% | 74% | 44.9% | 78.6% |
| ComBat | 22.3% | 31.6% | 36% | |
| OPNested | 14.7% | 29.8% | 22.6% | |
| OPNested + GMM | 6% | 39.5% | 16.5% | 13.5% |
| OPNested − GMM | 48.1% | 67% | 18.4% | 72.1% |
aNested Order: Manufacturer, Spatial Resolution, CE, Nested + GMM Order: Spatial Resolution, GMM, Manufacturer, CE, Nested – GMM Order: CE, Manufacturer, Spatial Resolution, GMM Feature: T1_E_GLRLM_ShortRunLowGreyLevelEmphasis.
bNested Order: CE, Spatial Resolution, Manufacturer, Nested + GMM Order: Spatial Resolution, CE, GMM, Manufacturer, Nested-GMM Order: Manufacturer, CE, Spatial Resolution, GMM Feature: ldmn.
cNested Order: Manufacturer, CE, Spatial Resolution, Nested + GMM Order: GMM, CE, Spatial Resolution, Manufacturer, Nested-GMM Order: Manufacturer, CE, Spatial Resolution, GMM Feature: T1_ED_GLRLM_Bins-10_Radius-1_ShortRunLowGreyLevelEmphasis.
dNested Order: Spatial Resolution, Manufacturer, CE, Nested + GMM Order: Spatial Resolution, GMM, Manufacturer, CE, Nested – GMM Order: CE, Spatial Resolution, Manufacturer, GMM Feature: JointEnergy.