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Giant Perivascular Spaces

Last Updated: October 1, 2018

Open Table of Contents: Giant Perivascular Spaces

Figure 1: Large, oval structure within the right putamen that follows CSF signal intensity on T1 (top row left), T2 (top row right), FLAIR (middle row left) and DWI (middle row right). Notice that there are a few additional similar-appearing smaller cystic structures medially, also representing dilated perivascular spaces. There is no significant adjacent FLAIR signal abnormality (middle row left) or enhancement (bottom row) to suggest an alternative diagnosis.


  • Pia-lined interstitial fluid filled spaces
  • Do not communicate with subarachnoid space


  • Fluid accumulation causing cystic-appearing spaces

Clinical Features

  • Symptoms
    • Almost always normal, though patients may have headache
    • May have association with small vessel disease and hemorrhage
  • Age

    • No age predilection
  • Gender

    • M > F


  • General
    • Variably-sized fluid-filled spaces with the signal of CSF
  • Modality Specific

    • CT
      • Round or even linear hypodense lesions with similar characteristics to CSF
      • Nonenhancing
  • MR

    • T1WI
      • Multiple well-delineated small cysts isointense to CSF
      • May have cumulative focal mass effect, particularly if involving the basal ganglia
    • T2WI/FLAIR

      • Isointense to CSF without surrounding edema
    • DWI

      • Normal diffusivity
    • Contrast

      • No enhancement
  • Imaging Recommendations

    • MR with contrast
    • DWI can be helpful
  • Mimic

    • May mimic infection, lacunar infarct or even cystic tumor. Location is often a key to the correct diagnosis, but MRI may help by demonstrating identical signal intensity to normal CSF and a lack of surrounding gliosis or enhancement.

For more information, please see the corresponding chapter in Radiopaedia.

Contributor: Sean Dodson, MD

DOI: https://doi.org/10.18791/nsatlas.v1.03.02.15


Eluvathingal Muttikkal TJ, et al. Spontaneous regression and recurrence of a tumefactive perivascular space. Neuroradiol J. 2014; 27(2):195-202.

John S, et al. Tumefactive perivascular spaces mimicking cerebral edema in a patient with diabetic hyperglycemia hyperosmolar syndrome: a case report. Journal of Medical Case Reports. 2013; 7:51. 10.1186/1752-1947-7-51.

Salzman KL, et al. Giant Tumefactive Perivascular Spaces. AJNR. 2005; 26: 298-305.

Stephens T, et al. Giant Tumefactive Perivascular Spaces. J Neurol Sci. 2008; 266(1-2):171-3.

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