Examples of tumor classifications are as follows: circumscribed, with sharp smooth borders (A); circumscribed, with sharp borders, but not smooth due to the extent of concave inward borders (B); circumscribed with sharp borders on T2-weighted image (C) but ... Examples of tumor classifications are as follows: circumscribed, with sharp smooth borders (A); circumscribed, with sharp borders, but not smooth due to the extent of concave inward borders (B); circumscribed with sharp borders on T2-weighted image (C) but not on T1-weighted image (D); partially circumscribed, with indistinct borders, but not smooth due to the extent of concave inward borders (E); and circumscribed, with predominantly sharp borders, but not smooth due to the extent of concave inward borders (F). All images are T2-weighted, except D as indicated. D.R. Johnson et al. AJNR Am J Neuroradiol 2017;38:678-684 ©2017 by American Society of Neuroradiology