Fig 2.

Postoperative findings after GBM resection in the right parietal lobe (not shown) in a 55-year-old man. A, Axial contrast-enhanced T1-weighted image in the immediate postoperative period demonstrates a fluid-filled surgical cavity (arrow) without any enhancing lesions, which is defined as gross total resection. B, An axial diffusion-weighted image shows marked restricted diffusion in the margins of the cavity (arrowhead), representing cytotoxic edema related to surgical manipulation. C, Axial contrast-enhanced T1-weighted image obtained 3 months after an operation shows the development of an enhancing focus in the surgical bed (arrowhead), corresponding to development of granulation tissue in the area of previously restricted diffusion, also a typical and predictable postoperative feature, which should not be misdiagnosed as recurrent or residual tumor.