Figure 1.

Diffuse large B-cell lymphoma in the corpus callosum. An axial T1 image after intravenous gadolinium administration (A) shows a homogeneous enhanced mass in the splenium of the corpus callosum, which is predominantly in the right hemisphere (arrow). An axial apparent diffusion coefficient map (B) confirmed a very low signal intensity in the solid lesion. Note the hyperintensity of the perilesional vasogenic edema. Proton magnetic resonance spectroscopy (C) shows decreased N-acetylaspartate levels and high choline/N-acetylaspartate and choline/creatinine ratios. Note the increased lipid and lactate peaks (0.9–1.3 ppm). A magnetic resonance perfusion sequence (dynamic susceptibility contrast magnetic resonance image T2*) (D) confirmed the absence of neoangiogenesis (low relative cerebral blood volume). Note the high percentage of signal intensity recovery (the ascending part of the curve above the baseline as indicated by the vertical arrowheads).