Vessel wall contrast enhancement: a diagnostic sign of cerebral vasculitis

Abstract

Purpose: Inflammatory stenoses of cerebral arteries cause stroke in patients with florid vasculitis. However, diagnosis is often difficult even with digital subtraction angiography (DSA) and biopsy. The purpose of this study was to establish the value of contrast-enhanced MRI, proven to be sensitive to extradural arteritis, for the identification of intracranial vessel wall inflammation.

Patients and methods: Twenty-seven patients with a diagnosis of cerebral vasculitis affecting large brain vessels were retrieved from the files: 8 children (2-10 years, 7 female, 1 male) and 19 adults (16-76 years, 10 female, 9 male). Diagnosis was based on histological or serological proof of vasculitis or on clinical and imaging criteria. All MRI examinations included diffusion-weighted imaging, time-of-flight magnetic resonance angiography (TOF-MRA) and contrast-enhanced scans. MRI scans were assessed for the presence of ischemic brain lesions, arterial stenoses, vessel wall thickening and contrast uptake.

Results: Ischemic changes of the brain tissue were seen in 24/27 patients and restricted diffusion suggestive of recent ischemia in 17/27; 25/27 patients had uni- or multifocal stenoses of intracranial arteries on TOF-MRA and 5/6 had stenoses on DSA. Vessel wall thickening was identified in 25/27, wall enhancement in 23/27 patients.

Conclusion: Wall thickening and intramural contrast uptake are frequent findings in patients with active cerebral vasculitis affecting large brain arteries. Further prospective studies are required to determine the specificity of this finding.

Fig. 1.

cPACNS; mild right hemispheric stroke with hemiparesis 10 days earlier; 4-year-old girl. a DWI. There is restricted diffusion of protons in the right basal ganglia. b The T₂-weighted MRI shows only minor hyperintense signal change in the basal ganglia on the right sparing the internal capsule. c The contrast-enhanced coronal T₁-weighted image (slice thickness 3 mm, flow compensation) after contrast injection (0.1 mmol/kg Gd-DTPA) through the distal internal carotid artery shows contrast enhancement in the right caudate and lentiforme nuclei. There is clearly enhancement in the wall of the right distal internal carotid artery (arrow). d The axial T₁-weighted image shows wall enhancement in the right distal internal carotid artery and the right P1 segment (arrow). e The TOF-MRA shows an abnormality of the right internal carotid artery around the carotid T, but also some narrowing in the right P1 (arrow).

Fig. 2.

Fifty-three-year-old woman with right-sided hemiparesis and aphasia. a–d High-resolution T₁-weighted images after contrast injection (0.1 mmol/kg) with fat suppression and flow compensation. a This T₁-weighted contrast-enhanced image at the level of the skull base shows an enlargement of the left distal internal carotid artery (arrow) compared to the right. b At a slightly higher location, there is contrast enhancement in the M1 segment on the left (arrow). c Wall enhancement is also seen in middle cerebral artery branches in the left sylvian fissure (arrow). d This image slightly more apical confirms the intramural enhancement pattern (arrow). e The TOF-MRA shows severe flow abnormality in the left distal internal carotid artery and A1 as well as M1 segments. There are also severe stenoses on the right.