Figure 1:

CE T1-weighted MR image (T1w MRI) in a 44-year-old female patient with recurrent GBM demonstrates an apparent reduction in contrast enhancement after bevacizumab therapy. A, Nonenhanced (Pre-Contrast) T1-weighted MR image. B, CE (Post-Contrast) T1-weighted MR image. C, Subtraction map. D, CE T1-weighted subtraction (CE-ΔT1w) map shows demarcation of an area of residual tumor identified as a positive increase in MR signal intensity after administration of contrast agent. Post-Pre = difference between after bevacizumab therapy and before bevacizumab therapy.