Simplified intravoxel incoherent motion DWI for differentiating malignant from benign breast lesions

European Radiology Experimental

Table 5 Results of the receiver operating characteristic analysis for the differentiation between benign and malignant lesions for group A+B versus group C

Test variable	Numbers	AUC	Standard error^a	Asym. sign.	Asym. 95% CI		Cutoff point	Sensitivity	Specificity	Accuracy
Test variable	Numbers	AUC	Standard error^a	Asym. sign.	Lower bound	Upper bound	Cutoff point	Sensitivity	Specificity	Accuracy
Vital tumour ROIs
ADC	86 versus 105	0.817	0.039	< 0.001	0.740	0.893	1,328.5	0.971	0.756	0.874
D₁′	86 versus 105	0.819	0.038	< 0.001	0.743	0.894	1,238.7	0.952	0.767	0.869
D₂′	86 versus 105	0.826	0.037	< 0.001	0.752	0.900	1,167.8	0.962	0.756	0.869
f₁′ #	86 versus 105	0.795	0.035	< 0.001	0.726	0.865	30.6	0.876	0.709	0.801
f₂′ #	86 versus 105	0.789	0.036	< 0.001	0.719	0.860	72.2	0.895	0.674	0.796
D*′ #	73 versus 105	0.613	0.044	0.010	0.526	0.700	12,912.4	0.810	0.425	0.652
D₁′+f₁′	86 versus 105						1,238.7/30.6	0.829	0.930	0.874
D₂′+f₂′	86 versus 105						1,167.8/72.2	0.867	0.919	0.890
Hot spot ROIs
ADC	86 versus 105	0.812	0.039	< 0.001	0.734	0.889	1,327.2	0.952	0.767	0.869
D₁′	86 versus 105	0.826	0.037	< 0.001	0.753	0.900	1,229.2	0.971	0.767	0.880
D₂′	86 versus 105	0.836	0.036	< 0.001	0.765	0.907	1,135.1	0.971	0.767	0.880
f₁′ #	86 versus 105	0.905	0.023	< 0.001	0.860	0.950	40.5	0.971	0.756	0.874
f₂′ #	86 versus 105	0.881	0.026	< 0.001	0.830	0.932	90.7	0.905	0.767	0.843
D*′ #	73 versus 105	0.707	0.040	< 0.001	0.629	0.785	16,900.6	0.771	0.603	0.702
D₁′+f₁′	86 versus 105						1,229.2/40.5	0.943	0.930	0.937
D₂′+f₂′	86 versus 105						1,135.1/90.7	0.876	0.942	0.906

The optimal cutoff point according the Youden index is given in 10^-6 mm²/s for ADC, D₁′, D₂′, and D*′ and in 10^-3 for f₁′ and f₂′, whereby a lower test result indicates a more ‘positive’ test (a negative test direction is marked with #). Sensitivity, specificity and accuracy are given for each parameter and for the combined parameter use D₁′+f₁′ and D₂′+f₂′, whereby lesions were assigned as malignant, if both parameters fulfilled the criterion of malignancy using the cutoff values determined for the single parameters. AUC Area under the curve, ^aUnder the non-parametric assumption, Asym. sign. Asymptotic significance (null hypothesis: true area = 0.5), Asym. 95% CI Asymptotic 95% confidence interval