Vessel Wall MRI in Pediatric Arterial Ischemic Stroke: Diagnostic Utility and Prognostic Value

BACKGROUND: Vessel wall magnetic resonance imaging (VW-MRI) is a promising tool for evaluating intracranial arteriopathies in pediatric non-neonatal arterial ischemic stroke, but its diagnostic and prognostic roles remain underexplored. This study assesses the utility of VW-MRI in identifying arteriopathy subtypes and predicting clinical and radiological outcomes in children. METHODS: We conducted an ancillary retrospective study using the national KidClot cohort and the stroke database at Necker-Enfants Malades Hospital (Paris). Children with arterial ischemic stroke who underwent VW-MRI within 3 months of onset and follow-up MRI at least 18 months later were included. Stroke causes were assessed according to the Childhood Arterial Ischemic Stroke Standardized Classification and Diagnostic Evaluation, and intracranial arterial vessel wall enhancement (VWE) was evaluated. Analyses focused on the focal cerebral arteriopathy (FCA) subgroup, comparing VWE-positive and VWE-negative patients and assessing correlations with clinical factors, imaging metrics, and outcomes. Categorical variables were compared using the χ 2 /Fisher exact test, qualitative/ordinal variables using the Mann-Whitney U test, and correlations were assessed using the Spearman rank correlation coefficient (ρ). RESULTS: From 193 children, 67 were included (median age, 4.1 years, interquartile range, 2.0–9.8; 61.1% male). Causes were FCA (42%, 28/67), bilateral cerebral arteriopathy (5%, 3/67), aortic/cervical arteriopathy (12%, 8/67), cardioembolic (7%, 5/67), other (22%, 15/67), and multifactorial (12%, 8/67). In FCA, 75% (21/28) showed concentric VWE, correlating with stenosis severity (ρ=0.31; P =0.001). VWE-positive patients with FCA had a higher initial focal cerebral arteriopathy severity score (median 5 versus 3; P =0.046) than VWE-negative patients, but no statistically significant differences were found in other evaluated factors, including initial Pediatric National Institutes of Health Stroke Scale (median 8.5 versus 8; P =0.5) and 12-month Pediatric Stroke Outcome Measure (median 0.5 versus 1; P =0.8). CONCLUSIONS: VW-MRI detects inflammatory arterial changes in pediatric FCA. However, its prognostic value is limited, suggesting enhancement reflects acute inflammation rather than long-term trajectory.