In what follows, we selected the best window size for each feature set and plotted their ROC curves all in Fig. 9 . Superiority of the proposed shape features is clear in all cases. To have a valid comparison, we repeated candidate selection step for all the methods because we observed that the CAD performances of compared conventional feature sets had much lower accuracies if the candidate selection part was not applied (i.e., proposed method's accuracy was decreased to A z = 0.6803, while the best result of all compared methods were decreased to A z < 0.5281). To show whether the proposed method was significantly different than the other methods, we compared the performances through paired t-tests. p-values of the tests indicate that none of the feature set are significantly correlated with the proposed CAD features such that highest and smallest pvalues are reported as 0.0195 (p < 0.05) and 0.0053 (p < 0.01), respectively.