"Tumefactive perivascular spaces are a rare finding of enlargement of perivascular spaces. It is important to recognise this condition as it can be easily mistaken for a neoplasm. Also, in rare cases, local mass effect from TPVS can cause complications."
"Although TPVS is a rare entity, MRI features are characteristic: a cluster of uniform or variable-sized cysts that follows CSF signal intensity on all MRI sequences 1. Associated mild surrounding increased T2 signal and gyral expansion are not uncommon, depending on the extent of lesions. The orientation of the cysts may follow a radial pattern aligned in the direction of the perforating arterioles."
"Coronal images are most useful in demonstrating the radial orientation of basal ganglia and thalamic TPVS along the direction of lenticulostriate perforators. Gliosis may be seen in the adjacent white matter with a minor increase in signal intensity on the T2 or FLAIR sequence 1. No enhancement should be demonstrated 1."
"Midbrain TPVS is aligned in the direction of the thalamostriate perforators, and these may be more oval in shape on axial images. Rare complications of cerebral aqueduct stenosis with ensuing obstructive hydrocephalus have been reported in the literature 1."