Figure 3.

Morphologic characteristics of the perivascular spaces. (A) Type III-midbrain type: Axial T2WI showed multiple linear EPVS (white arrow) with high intensity in the midbrain, which were generally symmetrically distributed on both sides and consistent with the course of the penetrating arteries. (B) In a 62-year-old woman, axial T2WI showed a large EPVS in the left precribrum with sac-like high intensity, within which a linear hypointense vessel can be seen, namely “vessel sign” (white arrow). (C) Axial T2WI revealed multiple linear and ovoid EPVS clustered locally near the right lateral ventricle (white arrow). (D,E) In a 76-year-old man with a history of hypertension and diabetes mellitus for many years, EPVS (white right angle arrow), WMH (black arrow), and small lacune (white arrow) were simultaneously present in the left centrum semiovale. The lacune (white arrow) showed a hyperintense rim around the vesicular cavity on FLAIR sequence, which can be distinguished from EPVS. (F) A 32-year-old male with cerebral cleft malformation combined with hypoplasia of the corpus callosum in the left cerebral hemisphere, who had recurrent headaches for many years. Multiple tumefactive PVS (white arrow) were seen in the subcortical white matter areas, and the lesions were unchanged on follow-up reviews of brain MR.