FIG 4. 65-year-old man with biopsy-proved low-grade oligodendroglioma.

A–C, Axial nonenhanced CT image through the frontal lobes (A), as well as axial contrast-enhanced T1-weighted (B) and rCBV (C) MR images through the same region, demonstrate a calcified left frontal mass (arrow in A). There is trace contrast enhancement and increased blood volume compared with the adjacent gray and white matter. The combination of calcification, relatively mild contrast enhancement, and increased rCBV is not uncommon for oligodendrogliomas of any grade.