RT Journal Article SR Electronic T1 How Flow Reduction Influences the Intracranial Aneurysm Occlusion: A Prospective 4D Phase-Contrast MRI Study JF American Journal of Neuroradiology JO Am. J. Neuroradiol. FD American Society of Neuroradiology SP 2117 OP 2123 DO 10.3174/ajnr.A6312 VO 40 IS 12 A1 O. Brina A1 P. Bouillot A1 P. Reymond A1 A.S. Luthman A1 C. Santarosa A1 M. Fahrat A1 K.O. Lovblad A1 P. Machi A1 B.M.A. Delattre A1 V.M. Pereira A1 M.I. Vargas YR 2019 UL http://www.ajnr.org/content/40/12/2117.abstract AB BACKGROUND AND PURPOSE: Flow-diverter stents are widely used for the treatment of wide-neck intracranial aneurysms. Various parameters may influence intracranial aneurysm thrombosis, including the flow reduction induced by flow-diverter stent implantation, which is assumed to play a leading role. However, its actual impact remains unclear due to the lack of detailed intra-aneurysmal flow measurements. This study aimed to clarify this relationship by quantitatively measuring the intra-aneurysmal flow using 4D phase-contrast MR imaging.MATERIALS AND METHODS: We acquired prospective pre- and post-stent implantation 4D phase-contrast MR imaging data of a consecutive series of 23 patients treated with flow-diverter stents. Velocity field data were combined with the intraprocedural 3D angiogram vessel geometries for precise intracranial aneurysm extraction and partial volume correction. Intra-aneurysmal hemodynamic modifications were compared with occlusion outcomes at 6 and 12 months.RESULTS: The averaged velocities at systole were lower after flow-diverter stent implantation for all patients and ranged from 21.7 ± 7.1 cm/s before to 7.2 ± 2.9 cm/s after stent placement. The velocity reduction was more important for the group of patients with aneurysm thrombosis at 6 months (68.8%) and decreased gradually from 66.2% to 55% for 12-month thrombosis and no thrombosis, respectively (P = .08).CONCLUSIONS: We propose an innovative approach to measure intracranial flow changes after flow-diverter stent implantation. We identified a trend between flow reduction and thrombosis outcome that brings a new insight into current understanding of the flow-diversion treatment response.CFDcomputational fluid dynamics3DRA3D rotational angiographyFDSflow-diverter stentIAintracranial aneurysmPCMRphase-contrast MRIPVRRproportional velocity-reduction ratioQICAICA systolic flow rates ratioQ̅ICAICA mean flow ratesVelanintra-aneurysmal velocityVENCvelocity encoding