Figure 1: Large oval structure within the right putamen that follows CSF signal intensity on T1-weighted (top left), T2-weighted (top right), FLAIR (middle left), and DWI (middle right) imaging. Notice that there are a few additional smaller similar-appearing cystic structures medially, also representing dilated perivascular spaces. There is no significant adjacent FLAIR signal abnormality (middle left) or enhancement (bottom) to suggest an alternative diagnosis.
- Pia-lined interstitial fluid-filled spaces
- Do not communicate with subarachnoid space
- Fluid accumulation causing cystic-appearing spaces
- Almost always normal, although patients may have headache
- Can have an association with small-vessel disease and hemorrhage
- Variably sized fluid-filled spaces with the signal of cerebrospinal fluid (CSF)
- Modality specific
- Round or even linear hypodense lesions with characteristics similar to those of CSF
- Multiple well-delineated small cysts isointense to CSF
- Can have cumulative focal mass effect, particularly if involving the basal ganglia
- Isointense to CSF without surrounding edema
- Imaging recommendations
- MRI with contrast
- DWI can be helpful
- Can mimic infection, lacunar infarct, or even cystic tumor; location is often a key to the correct diagnosis, but MRI might 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
Eluvathingal Muttikkal TJ, Raghavan P. Spontaneous regression and recurrence of a tumefactive perivascular space. Neuroradiol J 2014;27:195–202. doi.org/10.15274/NRJ-2014-10034
John S, Samuel S, Lakhan SE. Tumefactive perivascular spaces mimicking cerebral edema in a patient with diabetic hyperglycemic hyperosmolar syndrome: a case report. J Med Case Rep 2013;7:51. doi.org/10.1186/1752-1947-7-51
Salzman KL, Osborn AG, House P, et al. Giant tumefactive perivascular spaces. AJNR Am J Neuroradiol 2005;26:298–305.
Stephens T, Parmar H, Cornblath W. Giant tumefactive perivascular spaces. J Neurol Sci 2008;266:171–173. doi.org/10.1016/j.jns.2007.08.032
Please login to post a comment.