Abscess (brain): definition and imaging appearance on T1, T2, CE, and DWI
A. Fluid-filled sac; hyperintense on T1, hypointense on T2, enhanced on CE, hyperintense on DWI
B. Pus-filled cavity; hypointense on T1, hyperintense on T2, enhanced on CE, hyperintense on DWI
C. Solid mass; hypointense on T1, hyperintense on T2, not enhanced on CE, hyperintense on DWI
D. Calcified structure; hyperintense on T1, hypointense on T2, enhanced on CE, hypointense on DWI