perivascular space
Also written as: VRS — Virchow-Robin Space
Fluid-filled spaces surrounding penetrating arteries and veins, visible as linear hyperintensities on T2-weighted images.
Full Definition
Perivascular spaces, also known as Virchow-Robin spaces, are cerebrospinal fluid-filled cavities that surround penetrating arteries and veins as they enter the brain parenchyma. These spaces facilitate interstitial fluid drainage and are part of the brain's glymphatic system. On MRI, enlarged perivascular spaces appear as linear or punctate hyperintensities on T2-weighted images that follow the course of blood vessels and suppress completely on FLAIR sequences. While small perivascular spaces are normal, their enlargement may indicate impaired cerebrospinal fluid drainage or small vessel disease.
Usage
Usage note: Should suppress completely on FLAIR sequences unlike pathological lesions.
In Context
- "Prominent perivascular spaces in the basal ganglia were noted, consistent with the patient's age." — elderly patient brain MRI
- "The lesions followed vascular anatomy and suppressed on FLAIR, confirming they were enlarged perivascular spaces rather than infarcts." — differential diagnosis report