Male, 34 years old, with known although astrocytoma and seizures. A large left frontal lobe resection cavity is redemonstrated showing no significant change in size or morphology. Scattered foci of susceptibility are again seen surrounding the cavity compatible with chronic hemosiderin.Since the prior examinations, however, T2 signal abnormality and nodular enhancing tissue along the lateral margin of the cavity have progressed. The dominant nodular lesion shows correlating elevated rCBV. Progressive T2 signal abnormality and ill-defined enhancement is also seen posterior to the resection cavity, again with correlating elevated rCBV.Scattered additional areas of infiltrative T2 signal, tissue thickening and variable enhancement have also progressed including within the splenium of the corpus callosum and at the level of the hypothalamus. These areas are not well assessed on rCBV maps.Most notably, however, is extensive progressive T2 signal abnormality and irregular enhancement inferior to the resection cavity with extension into the basal ganglia and insula. Interestingly, little if any mass effect is detected. Furthermore, these tissues demonstrate markedly reduced rCBV, and single voxel spectroscopic assessment shows prominent lipid peaks but no other reliably detectable metabolites.The right lateral ventricle is shunted and decompressed. Mild ex vacuo dilatation of the left lateral ventricle is seen. The remaining ventricles are unremarkable. Mild T2 hyperintensity is seen surrounding the right frontal horn which is unchanged and nonspecific.
Evidence of a prior left frontal lobe tumor resection is demonstrated. Since the prior examinations, several changes are noted. For example, nodular enhancing tissue along the lateral margin of the cavity, and ill-defined enhancement with T2 signal abnormality along the posterior margin of the cavity, have progressed. Both areas demonstrate correlating elevated rCBV which would favor progressive tumor over treatment effect.Additional scattered areas of progressive signal abnormality and/or enhancement are seen involving the splenium of the corpus callosum and particularly the hypothalamus which is clearly thickened. For technical reasons, these areas are not well assessed on rCBV mapping. However, the distribution and morphology of the changes would also favor progressive tumor over treatment effect.Inferior to the resection cavity, however, extensive progressive T2 signal abnormality and enhancement is seen with a notable lack of significant mass effect. Furthermore, this tissue demonstrates reduced rCBV and a spectroscopic pattern consistent with predominant necrosis. As such, it is possible that these findings may reflect treatment related change/radiation necrosis.