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Heavy T2-weighted spin-echo inverted image of dilated perivascular space

Dilated perivascular (Virchow-Robin) space is an extension of the subarachnoid space around vessels perforating into the brain parenchyma. It is frequently detected along the path of the lenticulostriate arteries as they enter the basal ganglia through the anterior perforated substance.1,2 On MRI it appears as a round, oval, or curvilinear lesion with well-defined, smooth margins. It is usually smaller than 5 mm in diameter and shows no mass effect. The signal characteristics are identical to those of nonflowing CSF on all pulse sequences.1

It is often difficult, on the basis of MRI appearance alone, to distinguish dilated perivascular space from other cystic lesions such as lacunar infarction. Visualization of the vessel within the CSF-filled lesion, implying flow, would be conclusive for the diagnosis of dilated perivascular space. Here we present two patients in whom the vessel within the lesion was visualized by using heavy T2-weighted spin-echo inverted images.

Patient 1. A 57-year-old woman with no relevant history developed a headache over several days. Pain was diffuse but remained more severe in the …