Figure 5. Prominent perivascular spaces. A 75-year-old man with vascular dementia. Axial FLAIR image (A) shows small foci with signal intensity similar to CSF in all sequences, detected in the cerebral white matter, especially in the right parietal lobe. Note one of these foci, which has a rounded morphology (arrow) and is surrounded by T2/FLAIR hyperintensities. This appearance could be more suggestive of a lacune, however, the corresponding coronal T2-weighted image (B) shows that this lesion is elongated (arrow), most probably also corresponding to prominent perivascular spaces. This case illustrates the difficulties usually found in this differentiation.