Giant perivascular spaces: utility of MR in differentiation from other cystic lesions of the brain.

Perivascular or Virchow-Robin spaces (VR) of the brain are fluid-filled, pial-lined spaces that accompany the cerebral vessels as they pass from subarachnoid space into the brain parenchyma. They are visualized on routine MR examinations as CSF intensity spaces and are normally < 2 mm in size. These spaces may rarely enlarge massively and can be mistaken for more ominous pathologic processes on CT scan and even on MRI, but careful examination on special sequences and follow-up examination can clear the uncertainty. We describe a case of a young male who presented with mildly progressive neurological symptoms and the imaging findings were typical of enlarged VR spaces. Patient was advised follow up and is doing well.