Fig. 2

Kaplan–Meier curves of the training (a1, b1, and c1) and validation (a2, b2, and c2) cohorts, with patients divided into low- and high-risk groups, respectively. These were based on the median Rad score (a1 and a2) of 0.46, median clinical score (B1 and B2) of 0.08, and median integrative score (c1 and c2) of 0.17. Small vertical tick marks on the plot indicate individual patients whose survival probabilities have been right censored. A higher score represents higher risk. a1 and a2 curves suggest that the radiomic signature is significantly associated with stroke-free survival in both cohorts. For b1 and b2, the clinical signature had a significant association with stroke-free survival only in the training cohort but showed poor separation performance in the validation cohort. Regarding c1 and c2, the integrative signature had a more significant association with stroke-free survival than the other two signatures for both training and validation cohorts. Rad score, radiomic score