Male, 55 years old, history of anaplastic astrocytoma, status post radiation, on temozolomide. The T2 hyperintense lesion within the thalamus shows no significant interval change in size or morphology over multiple prior examinations. A biopsy marker remains evident in the center of the lesion. The lesion demostrates intrinsic T1 hyperintensity with little if any true superimposed enhancement.A subcentimeter enhancing focus along the margin of the left ventricular atrium has decreased in size and conspicuity relative to prior exams.Ill-defined periventricular white matter T2 hyperintensity along the left lateral ventricle is stable when compared to the immediate prior examination, but shows slight expansion in geographic extent when compared to older exams. Some of this signal abnormality was evident on the patient's initial pretreatment studies.A 6 mm curvilinear area of T2 hyperintensity is seen within the left paramedian precentral gyrus, not definitely changed in size when compared to the immediate prior examination but slightly more prominent than on older studies. Of note, however, is the fact that this lesion now enhances whereas previously it did not.Numerous additional scattered small foci of T2 signal abnormality are seen throughout both cerebral hemispheres, without significant or convincing interval change. No new mass effect or parenchymal edema is detected. Ventricles are stable in size including mild ex vacuo dilatation of the left lateral ventricle.
1.No significant interval change in the size or appearance of the left thalamic lesion.2.Decrease in size and enhancement of a nodule of enhancement along the left lateral ventricular atrium.3.Ill-defined left periventricular white matter T2 hyperintensity is stable relative to the immediate prior examination but slightly more extensive when compared to older exams. It should be noted that some of this signal abnormality was present on the initial pretreatment examinations and therefore it cannot be attributed entirely to treatment effect. The possibility that some of this signal abnormality may reflect non-enhancing tumor must be considered.4.A curvilinear region of T2 hyperintensity within the left paramedian precentral gyrus is unchanged in size relative to the immediate prior examination but slightly more conspicuous when compared to older studies. Of note, however, is the fact that this lesion shows new enhancement on today's examination. The lesion is too small to accurately characterize, but for the reasons indicated in impression point number 3, the possibility of viable tumor in this location must be considered. Other etiologies including treatment related vascular injury are not excluded. Close interval follow-up is suggested.