Calcification of the right thalamus and globus pallidus is associated with a branching draining vein (into the basal vein of Rosenthal at the level of the right superior colliculus) in keeping with a development venous anomaly. This is difficult to appreciate on DSA (not shown), which excludes a shunting AVM/dAVF. Prominent chronic small vessel ischaemic change noted. No focal mass or collection.
Conclusion: The CT and MRI abnormalities represent asymmetric mineralisation/calcification. There is a known associated with a developmental venous anomaly.