PT  - JOURNAL ARTICLE
AU  - O. Brina
AU  - P. Bouillot
AU  - P. Reymond
AU  - A.S. Luthman
AU  - C. Santarosa
AU  - M. Fahrat
AU  - K.O. Lovblad
AU  - P. Machi
AU  - B.M.A. Delattre
AU  - V.M. Pereira
AU  - M.I. Vargas
TI  - How Flow Reduction Influences the Intracranial Aneurysm Occlusion: A Prospective 4D Phase-Contrast MRI Study
AID  - 10.3174/ajnr.A6312
DP  - 2019 Dec 01
TA  - American Journal of Neuroradiology
PG  - 2117--2123
VI  - 40
IP  - 12
4099  - http://www.ajnr.org/content/40/12/2117.short
4100  - http://www.ajnr.org/content/40/12/2117.full
SO  - Am. J. Neuroradiol.2019 Dec 01; 40
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