Fig. 3

A 44-year-old clinically-stable male patient with an operated right parieto-frontal grade III astrocytoma finished chemoradiotherapy 6 months ago. a and b Axial FLAIR images of the first and second studies, respectively show stationary size of the FLAIR component with development of a higher signal in the resection cavity in the follow-up study. No significant changes in the surrounding mass effect. c and d Axial post-contrast T1 WIs of the first and second studies, respectively show an increase in the enhancing component by less than 25% in the follow-up study. e and f Coronal post-contrast T1 WIs of the first and second studies, respectively show an increase in the enhancing component. g and h Axial ADC maps show a decrease of ADCmean in the enhancing resection cavity margin (1.1 × 10⁻³mm²/s) and (0.9 × 10⁻³mm²/s) in the first and second studies, respectively. BT-RADS category 3b was given with an intermediate probability of tumor recurrence. Decrease ADCmean and higher FLAIR signal within resection cavity favor the possibility of tumor recurrence. Tumor progression was proved in the second stage follow-up study