Perivascular Space Enhancing Lesions
Karen L. Salzman, MD
DIFFERENTIAL DIAGNOSIS
Common
Meningitis
Neurosarcoid
Tuberculosis
Vasculitis
Less Common
Glioblastoma Multiforme
Lymphoma, Intravascular (Angiocentric)
Cerebral Amyloid Disease
Rare but Important
Metastases
Granulomatous Angiitis
Langerhans Cell Histiocytosis
Wegener Granulomatosis, Brain
Moyamoya (Mimic)
Meningioangiomatosis
Neurocutaneous Melanosis
ESSENTIAL INFORMATION
Key Differential Diagnosis Issues
Perivascular spaces (PVS) are pial-lined, fluid-filled structures that accompany penetrating arteries
PVS follow CSF on all MR sequences
Rarely an enhancing vessel may be seen centrally within the PVS as a normal variant
Enhancement of PVS is typically related to infection, vasculitis, or tumor
Age of patient may help differentiate lesions
Helpful Clues for Common Diagnoses
Meningitis
Enhancing leptomeninges typical
Hydrocephalus very common
Inflammatory cells may extend along PVS
More common in children
May cause an infectious vasculitis; infarction due to vasculitis in 25%
Neurosarcoid
Multisystem inflammatory disease characterized by noncaseating granulomas
Meningeal enhancement typical (leptomeningeal & dural)
May invade brain via PVS & cause diffuse or focal mass-like lesions
Periventricular T2 hyperintense lesions common (50%)
May cause a small vessel vasculitis (involves penetrating arteries)
Tuberculosis
Meningitis + parenchymal lesions common appearance
Inflammatory cells may extend along PVS
May cause an infectious vasculitis
Skull base vessels most commonly involved (supraclinoid ICA & M1)
Vasculitis
Heterogeneous group of CNS disorders with inflammation & blood vessel necrosis
Primary or secondary to systemic disease
Alternating stenosis, dilatation primarily involving 2nd, 3rd order branches
Angiography best for diagnosis
Multifocal ischemia in subcortical white matter (WM) & basal ganglia (BG)
May cause PVS enhancement
Helpful Clues for Less Common Diagnoses
Glioblastoma Multiforme
Peripherally enhancing, centrally necrotic WM mass typical
Often involves corpus callosum
May metastasize along PVS
Lymphoma, Intravascular (Angiocentric)
Rare malignancy characterized by intravascular proliferation of lymphoid cells with a predilection for CNS & skin
Multifocal T2 hyperintensity in deep WM, cortex, or BG + enhancement typical
May see cortical infarct-like lesions
May cause a vasculitis
Cerebral Amyloid Disease
Lobar hemorrhages of different ages & multifocal “black dots” typical
Amyloid deposits may occur along PVS
May cause a vasculitis
Occurs in elderly adults
Helpful Clues for Rare Diagnoses
Metastases
Multifocal parenchymal enhancement at gray-white interfaces typical
May rarely spread along PVS or involve meninges
Primary tumor often known
Granulomatous Angiitis
Primary angiitis isolated to the CNS (idiopathic)
Manifests as multiple intracranial stenoses
May cause PVS enhancement in BG or WM
Langerhans Cell Histiocytosis
Thick enhancing pituitary stalk is most common CNS manifestation
Lack of pituitary “bright spot”
May extend along PVS
Rarely causes enhancing choroid plexus, BG, &/or leptomeningeal nodules
Wegener Granulomatosis, Brain
Chronic systemic arteritis involving lungs, kidneys, & sinuses
CNS involved in 15-30% due to direct invasion from nose/sinuses
May cause intracerebral & meningeal granulomas or vasculitis
May cause meningeal & PVS enhancement
Moyamoya (Mimic)
Moyamoya is an angiographic pattern
Idiopathic progressive arteriopathy of childhood
Slowly progressive occlusion of the supraclinoid ICAs
T2 MR shows multiple dark flow voids in BG related to lenticulostriate collaterals
Contrast MR shows enhancement of these collaterals mimicking PVS enhancementRelated posts:
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