Magnetic resonance imaging features of unusually dilated Virchow-Robin spaces--two case reports.

Two patients presented with unusually dilated Virchow-Robin spaces appearing as cystic lesions of varying size with signal intensity identical to the cerebrospinal fluid on all magnetic resonance pulse sequences. However, fluid-attenuated inversion-recovery (FLAIR) images disclosed small, high intensity foci adjacent to these cystic lesions in one patient. These high intensity foci on FLAIR images may represent chronic ischemic change, which produces the gradual dilation of the Virchow-Robin spaces.