Male, 60 years old, new diagnosis of head and neck cancer, abnormal lesion in the left thalamus on CT. Assess for metastases. T1 hyperintensity and mild susceptibility artifact is seen within the pulvinar of the left thalamus with at most a slight expansion of the affected tissue. There is no convincing enhancement above and beyond the intrinsic T1 hyperintensity. However, a venous structure originates within this tissue and passes through it to drain to the vein of Galen. Minimal T2 hyperintensity is seen in this location without evidence of edema.No restricted diffusion is seen in the brain. No other areas of significant parenchymal signal abnormality are detected. At most, there may be a few scattered punctate foci of white matter T2 hyperintensity which are nonspecific. No mass or pathologic enhancement is detected. No abnormal extra axial collections are seen. The ventricles are normal in size and morphology.
Corresponding to the lesion seen on recent prior CT, intrinsic T1 hyperintensity and mild susceptibility artifact are seen within the pulvinar of the left thalamus. The lesion as a whole does not enhance. However, there is a developmental venous anomaly which originates within and passes through the lesion.The findings are most suggestive of an incidental cavernous malformation with associated developmental venous anomaly. Alternately, the abnormal signal could reflect a complication of the developmental venous anomaly without an associated cavernoma. Other processes are known to produce T1 hyperintensity in the pulvinar, including metabolic and endocrinologic conditions, but these are usually bilateral and symmetric.In any event, this lesion is not consistent with a metastatic deposit, and there is no evidence of any additional intracranial metastatic disease.