1naresh<pre>Array
(
    [urn:ac.highwire.org:guest:identity] => Array
        (
            [runtime-id] => urn:ac.highwire.org:guest:identity
            [type] => guest
            [service-id] => ajnr-ac.highwire.org
            [access-type] => Controlled
            [privilege] => Array
                (
                    [urn:ac.highwire.org:guest:privilege] => Array
                        (
                            [runtime-id] => urn:ac.highwire.org:guest:privilege
                            [type] => privilege-set
                            [privilege-set] => GUEST
                        )

                )

            [credentials] => Array
                (
                    [method] => guest
                )

        )

)
1naresh<pre>Array
(
    [urn:ac.highwire.org:guest:identity] => Array
        (
            [runtime-id] => urn:ac.highwire.org:guest:identity
            [type] => guest
            [service-id] => ajnr-ac.highwire.org
            [access-type] => OpenAccess
            [privilege] => Array
                (
                    [urn:ac.highwire.org:guest:privilege] => Array
                        (
                            [runtime-id] => urn:ac.highwire.org:guest:privilege
                            [type] => privilege-set
                            [privilege-set] => GUEST
                        )

                )

            [credentials] => Array
                (
                    [method] => guest
                )

        )

)
PT  - JOURNAL ARTICLE
AU  - Brina, O.
AU  - Bouillot, P.
AU  - Reymond, P.
AU  - Luthman, A.S.
AU  - Santarosa, C.
AU  - Fahrat, M.
AU  - Lovblad, K.O.
AU  - Machi, P.
AU  - Delattre, B.M.A.
AU  - Pereira, V.M.
AU  - Vargas, M.I.
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