Figure 4 (A-C).

Pseudoresponse. Recurrent glioma in a 63-year-old man. (A) Follow-up T2 (left) and contrast-enhanced (right) images show enhancing recurrence (arrows) in the splenium. (B) Imaging after six cycles of bevacizumab continues to show abnormal T2 signal in the splenium (biological tumor), despite marked regression of surrounding edema and of enhancement (pseudoresponse). (C) DW (diffusion weighted) (left) and ADC (right) images show restricted diffusion with reduced ADC values representing persistent biological tumor. The paradox between progressive non-enhancing tumor and decreasing enhancement is a recognized effect of antiangiogenic agents and is referred to as pseudoresponse