CNS Vasculitis Imaging Protocol

Recommended Imaging Approach

The American College of Radiology recommends a contrast-enhanced MRI brain with vessel wall imaging protocol plus time-of-flight MRA without contrast for detecting CNS vasculitis, as it is the most appropriate imaging approach 1, 2, 3
The American College of Radiology suggests that MRI brain with contrast, including standard brain sequences and post-contrast T1-weighted sequences, is a critical component of the imaging protocol 1, 2
Vessel wall imaging (VWI) sequences with contrast enhancement are essential for detecting inflammatory changes in vessel walls, with a diagnostic accuracy of 89% compared to 36% with luminal imaging alone 4, 3

MRI head is highly sensitive for CNS vasculitis, with sensitivity approaching 100% when normal, and key parenchymal findings include multiple infarcts of variable ages, progressive confluent white matter lesions, and cortical and subcortical T2/FLAIR hyperintensities 1, 2, 3
Time-of-flight MRA shows abnormalities in 81% of patients with angiographic findings of vasculitis, and can detect multifocal stenosis and dilatation of intracranial vessels 1, 3, 2

MRA has limited resolution for detecting small vessel involvement, and luminal imaging (MRA/CTA) alone has considerable overlap with other cerebrovascular diseases like atherosclerosis and reversible cerebral vasoconstriction syndrome 1, 3, 2
Conventional angiography (DSA) remains the historical gold standard for vessel imaging but has low specificity for vasculitis, and there is no evidence to support the use of MRA with IV contrast, MRA neck, MRI perfusion, or MRV head in the initial evaluation of suspected CNS vasculitis 2, 1, 3