Miscellaneous Vasculitis

KEY FACTS

TERMINOLOGY

• Heterogeneous group of CNS disorders

○ Characterized by nonatheromatous inflammation and

necrosis of blood vessel walls

○ Both arteries, veins may be affected

IMAGING

• CTA/MRA useful screening; spatial resolution usually

insufficient for subtle disease

• MR

○ Basal ganglia, cortex, subcortical white matter

– Multifocal hypodensities/T2 hyperintensities

– Look for secondary signs (ischemia/infarction)

○ High-resolution (3T, thin-section) T1 C+ may

demonstrate wall enhancement

– Smooth, concentric

– Long segment

– Distal involvement (e.g., M2, M3, M4 branches >

intracranial internal carotid artery and basilar artery)

– Multiple vessels usually affected

• DSA

○ Findings nonspecific (visualizes lumen, not vessel wall)

– Multifocal areas of smooth or slightly irregular-shaped

stenoses alternating with dilated segments

– May occur in intracranial vessels of any size

– Major differential diagnosis = intracranial

atherosclerosis

TOP DIFFERENTIAL DIAGNOSES

• Intracranial atherosclerotic vascular disease

• Arterial vasospasm

• Reversible cerebral vasoconstriction syndrome

PATHOLOGY

• Vessel wall inflammation, necrosis common to all

vasculitides

(Left) Axial FLAIR scan in a

case of secondary CNS

vasculitis shows multiple

hyperintense foci in the basal

ganglia, thalami, and cortex

ſt. (Right) Axial DWI MR in

the same case shows multiple

small foci of restricted

diffusion in the basal ganglia,

thalami, and cortex ſt.

(Left) Lateral view of the

internal carotid angiogram

obtained in the same case

shows multiple cortical vessels

﬊ with alternating areas of

stenosis and dilatation

("beading"). The findings are

consistent with multiple

infarcts secondary to

infectious (streptococcal)

vasculitis. (Right) 3T highresolution axial T1 C+ FS in a

59-year-old woman with

proven ANCA vasculitis shows

intense enhancement of the

distal internal carotid and

proximal middle cerebral

arteries ſt.

Trauma, and Stroke

Brain: Pathology-Based Diagnoses: Malformations,

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