Fig. 4. Kaplan-Meier survival curves of patients stratified by perfusion skewness and kurtosis for progression-free survival (A) and overall survival (B).

Patients were stratified by histogram patterns of pre-operative tumors into those with positive skewness and leptokurtosis (group 1), those with positive skewness and platykurtosis (group 2), those with negative skewness and leptokurtosis (group 3), and those with negative skewness and platykurtosis (group 4). Progression-free survival and overall survival tended to be longer in group 1.