Table 2.

Support vector machine (SVM) classification results (weak vs. strong responders) using different gray matter probability masks. Lower gray matter thresholds correspond to more inclusive masks.

Gray matter threshold	Accuracy in weak responders (%)	Accuracy in strong responders (%)	Total accuracy (%)	PPV	NPV
0.01	77.33	70.67	74.00	0.725	0.757
0.1	78.67	70.67	74.67	0.728	0.768
0.2	78.22	70.67	74.44	0.727	0.764
0.3	76.00	72.44	74.22	0.734	0.751
0.4	64.44	73.33	68.89	0.707	0.673
0.5	62.22	73.33	67.78	0.700	0.660

Note: NPV negative predictive value; PPV positive predictive value.