Fig. 4
From: Brain MR findings in patients treated with particle therapy for skull base tumors
MRI performed 13 months after proton therapy for clival chondrosarcoma. Axial fluid-attenuated inversion recovery (FLAIR) image (a) shows a disomogeneous area of altered signal, with hypo- and hyperintense components, located in the right hippocampal region and surrounded by extensive edema involving subcortical temporal and frontoinsular white matter, the cortico-spinal tract and causing mass effect on the right cerebral peduncle. Axial postcontrast T1-weighted image (b) shows peripheral and disomogenous enhancement, with “soap bubble” like pattern. rCBV (c) and CBF (d) maps show no hyperperfusion in the enhancing area. MRS-short TE (e) reveals the presence of high lipid and lactate peak with general decrease of other metabolites, highly suggestive for radiation necrosis. Control MRI performed in the same patient after 3 months; no intercurrent therapies. Axial FLAIR image (f) shows an evident decrease of the vasogenic edema, confined to temporal lobe. Axial T1-post contrast-weighted image (g) shows reduction in size of the enhancing lesion