. 2018 Jun 14;19(4):682–691. doi: 10.3348/kjr.2018.19.4.682

Table 3. Diagnostic Performance of DCE-MRI Histogram Metrics (Post-NAC and %Change) to Predict Good Response after NAC.

Metrics	Post-NAC						%Change
Metrics	Mean	25th Percentile	50th Percentile	75th Percentile	Skewness	Kurtosis	Mean	25th Percentile	50th Percentile	75th Percentile	Skewness	Kurtosis
K_trans
AUC	0.78	0.76	0.77	0.77	0.61	0.70	0.73	0.72	0.73	0.73	0.59	0.54
CI	0.60–0.96	0.57–0.94	0.58–0.95	0.58–0.95	0.43–0.79	0.53–0.87	0.54–0.92	0.53–0.91	0.54–0.91	0.54–0.91	0.40–0.77	0.34–0.75
Sensitivity	0.75	0.58	0.75	0.75	0.92	0.92	0.67	0.67	0.67	0.67	0.92	0.58
Specificity	0.81	0.93	0.78	0.81	0.44	0.56	0.85	0.81	0.85	0.81	0.44	0.59
p value	0.002^*	0.007^*	0.005^*	0.005^*	0.223	0.021^*	0.017^*	0.022^*	0.016^*	0.015^*	0.362	0.677
Cutoff	0.11	0.04	0.10	0.14	0.21	−0.81	−59.69	−63.26	−60.14	−59.60	−35.12	−17.91
K_ep
AUC	0.78	0.81	0.81	0.80	0.76	0.75	0.70	0.73	0.69	0.69	0.69	0.69
CI	0.63–0.93	0.67–0.94	0.67–0.95	0.66–0.95	0.59–0.93	0.57–0.93	0.54–0.86	0.58–0.89	0.53–0.86	0.53–0.86	0.5–0.87	0.49–0.9
Sensitivity	0.92	1	1	0.92	0.58	0.58	1	1	1	0.92	0.67	0.58
Specificity	0.56	0.59	0.59	0.59	0.89	0.89	0.48	0.52	0.48	0.52	0.78	0.85
p value	< 0.001^*	< 0.001^*	< 0.001^*	< 0.001^*	0.002^*	0.006^*	0.015^*	0.004^*	0.020^*	0.020^*	0.048^*	0.065
Cutoff	0.37	0.23	0.34	0.47	0.75	0.01	−16.92	−23.02	−19.32	−32.60	38.51	−102.36
V_e
AUC	0.43	0.61	0.42	0.45	0.70	0.61	0.53	0.63	0.56	0.50	0.55	0.59
CI	0.22–0.64	0.40–0.82	0.20–0.63	0.25–0.66	0.52–0.88	0.39–0.83	0.33–0.73	0.44–0.83	0.36–0.76	0.30–0.70	0.34–0.77	0.38–0.79
Sensitivity	0.50	0.50	0.50	0.50	0.50	0.50	0.58	0.75	0.58	0.58	0.33	0.33
Specificity	0.65	0.81	0.65	0.65	0.88	0.81	0.58	0.54	0.58	0.58	0.88	0.88
p value	0.505	0.314	0.442	0.643	0.029^*	0.327	0.774	0.166	0.552	> 0.999	0.615	0.406
Cutoff	0.51	0.29	0.50	0.62	0.75	0.24	−13.71	−12.58	−13.85	−9.20	130.61	−334.69

Optimal threshold was chosen according to Youden index. ^*Statistically significant differences (p < 0.05). %change = ([post-NAC values − pre-NAC values] / pre-NAC values) × 100.

AUC = area under ROC curve, CI = confidence interval, ROC = receiver operating characteristic