fig1

Figure 1. Top Row (A-C): Axial T1 post-contrast and FLAIR images with overlaid radiation treatment plan demonstrates an incomplete ring enhancing, FLAIR hyperintense lesion in the right posterior frontal lobe (A; arrow). There are also left frontal lobe juxtacortical non-enhancing white matter FLAIR hyperintense lesions (B, C; arrows) in the 1000-3000 cGy isodose zones. The imaging findings are consistent with acute demyelination. Middle Row (D-F): DCE perfusion MRI shows no significant increase in capillary permeability in the right posterior frontal lobe partially ring enhancing lesion (D; arrow). Dynamic susceptibility contrast perfusion MRI reveals no elevation of the rCBV in the lesion (E; arrow). MR spectroscopy demonstrates a choline to creatinine ratio < 2:1 and no significant depression of the NAA peak in the right posterior frontal lesion (F). The advanced imaging features also support demyelination. Bottom Row (G-I): Six months later, there is no longer enhancement associated with the right posterior parasagittal frontal lobe lesion (G, arrow) and there is interval decrease in size of the white matter FLAIR hyperintense lesions bilaterally (H, I; arrows)