FIG 3. Patient 9 with anaplastic oligodendroglioma.

A and B, Nonenhanced (A) and gadolinium-enhanced (B) SE T1-weighted images of the right temporal tumor. The gadolinium-enhanced image shows evidence of strong, lobulated peripheral enhancement with a central nonenhancing zone.

C, At 24 hours after ferumoxtran infusion, SE T1-weighted image demonstrates marked high signal intensity in a similar distribution but with less peripheral lobulation compared with the gadolinium-enhanced image. Also note that the non–gadolinium-enhancing central zone became isointense to white matter, suggesting some ferumoxtran accumulation.

D–F, Fast SE T2-weighted image obtained before ferumoxtran infusion (D) and fast SE T2-weighted (E) and GRE T2*-weighted (F) images obtained 24 hours after ferumoxtran infusion show a heterogeneous tumor mass with peripheral decreased signal intensity that is more prominent on the GRE T2*-weighted image. The distribution of the low-signal-intensity areas is similar to that of the high-signal-intensity areas on the SE T1-weighted image in C.

G and H, Photomicrographs from histologic staining for iron (DAB-enhanced Perls stain). In G (original magnification x7.5; bar indicates 1 mm), tumor (T) and reactive brain interface (RB) show the intense staining for iron at the periphery of the tumor. In H (original magnification x100; bar indicates 0.1 mm), cellular iron staining at the tumor–reactive brain interface shows iron uptake by the parenchymal cells with fibrillar processes (arrows) rather than by the round tumor cells (T).