SWI Susceptibility Vessel Sign in Patients Undergoing Mechanical Thrombectomy for Acute Ischemic Stroke

Abstract

BACKGROUND AND PURPOSE:The frequency and clinical significance of the susceptibility vessel sign in patients with acute ischemic stroke remains unclear. We aimed to assess its prevalence in patients with acute ischemic stroke undergoing mechanical thrombectomy and to analyze its association with interventional and clinical outcome parameters in that group.MATERIALS AND METHODS: Six hundred seventy-six patients with acute ischemic stroke and admission MR imaging were reviewed retrospectively. Of those, 577 met the eligibility criteria for further analysis. Imaging was performed using a 1.5T or 3T MR imaging scanner. Associations between baseline variables, interventional and clinical outcome parameters, and susceptibility vessel sign were determined with multivariable logistic regression models. Results are shown as adjusted ORs with 95% CIs. RESULTS:The susceptibility vessel sign was present in 87.5% (n = 505) of patients and associated with tandem occlusion (adjusted OR, 3.3; 95% CI, 1.1-10.0; P ¼ .032) as well as successful reperfusion, defined as an expanded TICI score of $2b (adjusted OR, 2.4; 95% CI, 1.28-4.6; P ¼ .007). The susceptibility vessel sign was independently associated with functional independence (mRS # 2: adjusted OR, 2.1; 95% CI, 1.1-4.0; P ¼ .028) and lower mortality (adjusted OR, 0.4; 95% CI, 0.2-0.7; P ¼ .003) at 90 days, even after adjusting for successful reperfusion. The susceptibility vessel sign did not influence the number of passes performed during mechanical thrombectomy, the first-pass reperfusion, or the risk of peri-or postinterventional complications. CONCLUSIONS:The susceptibility vessel sign is an MR imaging phenomenon frequently observed in patients with acute ischemic stroke and is associated with successful reperfusion after mechanical thrombectomy. However, superior clinical functional outcome and lower mortality noted in patients showing the susceptibility vessel sign could not be entirely attributed to higher reperfusion rates.

Absence of Susceptibility Vessel Sign in Patients With Malignancy-Related Acute Ischemic Stroke Treated With Mechanical Thrombectomy

“…Between January 2010 and December 2018, 1,317 patients with AIS were treated with MT at our stroke center. As already described by Belachew et al and shown in Supplementary Figure I (study flowchart), 577 patients had SWI with assessable SVS status available at admission and met the inclusion criteria ( 24 ). Evidence of active malignancy at the time of stroke was found in 40 patients (6.93%), of which a subset of 9 patients (1.56%) had occult malignancy.…”

“…Magnetom Verio 3T SWI was performed with the following parameters: TR, 27 ms; TE, 20 ms; flip angle, 15.0°; section thickness, 2.0 mm; and intersection gap, 0 mm. The detailed method used to determine the presence of SVS in the cohort analyzed in this article was described by N. Belachew et al in a previous publication ( 24 ). To summarize, SVS status was assessed retrospectively by two independent neuroradiologists (N.F.B.…”

“…If no such signal loss could be identified even though a symptomatic vessel occlusion was seen on angiography, SVS was determined to be absent ( Figures 1C,D ). Interrater reliability regarding SVS evaluation for the study cohort analyzed in this article has been assessed and published in a previous study showing very good correlation (Cohen's κ = 0.873, p < 0.001) ( 24 ).…”

Thrombus magnetic susceptibility is associated with recanalization and clinical outcome in patients with ischemic stroke

“…Most previous susceptibility-related MRI studies focused on the image signs like SVS ( Belachew et al, 2021 , Bourcier et al, 2015 , Bourcier et al, 2018 , Cho et al, 2005 , Darcourt et al, 2019 , Kang et al, 2017 , Liu et al, 2019 , Soize et al, 2015 ) due to the easy clinical availability. The present study is one of the first studies to explore the thrombus properties and outcome associations by the quantification MRI method.…”

“…The MRI susceptibility vessel sign (SVS), defined as the hypointense blooming signals on T2*-weighted or susceptibility-weighted imaging (SWI), demonstrates the existence of local paramagnetic contents such as deoxyhemoglobin and methemoglobin ( Cho et al, 2005 ). Many studies reported that patients with SVS receiving EVT were more likely to recanalize and improve clinical outcomes ( Belachew et al, 2021 , Bourcier et al, 2015 , Bourcier et al, 2018 , Darcourt et al, 2019 , Liu et al, 2019 ). However, on the same issue, several studies showed negative results ( Soize et al, 2015 , Kang et al, 2017 ).…”