Quantitative magnetic resonance angiography demonstrates persistent flow improvement following cerebrovascular stenting

Objective: While improved cerebral blood flow is expected following stent placement for cerebrovascular atherosclerotic disease, objective quantification of these hemodynamic changes remains limited. Quantitative magnetic resonance angiography (qMRA) offers a non-invasive, reproducible method to measure volumetric flow and evaluate both immediate and long-term hemodynamic effects of stenting. Methods: We retrospectively reviewed all patients who underwent stenting for cerebrovascular atherosclerotic disease using Onyx drug-eluting stents (DES) between January 2018 and September 2024. Demographics, clinical presentation and follow-up, radiographic findings, procedural details, and complications were collected. Outcomes assessed were procedural success, periprocedural stroke, in-stent restenosis (ISR) requiring reintervention, and qMRA flow measurements obtained pre-stenting, post-stenting, and at long-term follow-up. The median long-term follow-up duration was 9.4 months for qMRA. Results: A total of 63 patients with 84 Onyx DES were included (mean age 63.1±11.37 years; 33.3% female). The median number of stents deployed per patient was 1.0; mean stent length and diameter were 11.02±3.92 mm and 2.5±0.88mm, respectively. ISR occurred in 15.9% of patients. Technical and clinical complications each occurred in 4.8% of patients. qMRA across all vessels demonstrated a significant increase in flow post-stent and remained elevated at long-term follow-up. Vessel-specific analysis confirmed significant and persistent post-stent flow augmentation in the basilar, vertebral (VA), middle cerebral, and internal carotid arteries (ICA). Although mean VA and ICA flow declined modestly from post-stent to long-term follow-up, values remained markedly elevated compared to pre-stent baselines and flow augmentation was comparable across vessels. Conclusions: qMRA demonstrated robust, persistent improvements in cerebral blood flow following Onyx stenting for cerebrovascular atherosclerotic disease.