The Association between FLAIR Vascular Hyperintensity and Stroke Outcome Varies with Time from Onset

Abstract

BACKGROUND AND PURPOSE: FLAIR vascular hyperintensity has been recognized as a marker of collaterals in ischemic stroke, but the impact on outcome is still controversial. We hypothesized that the association between FLAIR vascular hyperintensity and outcome varies with time. MATERIALS AND METHODS: We included 459 consecutive patients with middle cerebral artery stroke and divided them into 3 groups by symptom-to-MR imaging time (group 1, Յ7 days; group 2, 8-14 days; group 3, Ն15 days). The FLAIR vascular hyperintensity score, ranging from 0 to 3 points, was based on territory distributions of different MCA segments. The associations between FLAIR vascular hyperintensity and outcome with time were analyzed qualitatively and quantitatively. RESULTS: No patients underwent MR imaging within 6 hours of onset. The proportion of FLAIR vascular hyperintensity (ϩ) and severe stenosis or occlusion of MCA was not significantly dependent on time. In groups 1 and 2, FLAIR vascular hyperintensity (ϩ) was significantly associated with larger lesions, the prevalence of flow injury, and unfavorable outcome (mRS Ն 2). There were no such associations in group 3. Multiple logistic regressions demonstrated that FLAIR vascular hyperintensity (ϩ) was an independent risk factor for unfavorable outcome in group 2. Infarction volume tended to increase with the increase of the distal FLAIR vascular hyperintensity score in groups 1 and 2, while declining in group 3. CONCLUSIONS: FLAIR vascular hyperintensity is associated with unfavorable outcome within 6 hours to 14 days of onset, while the wider distribution of distal FLAIR vascular hyperintensity may be favorable beyond 14 days of onset in MCA infarction. Symptom-to-MR imaging time should be considered when assessing the prognostic value of FLAIR vascular hyperintensity.

Fluid-Attenuated Inversion Recovery Vascular Hyperintensity in Cerebrovascular Disease: A Review for Radiologists and Clinicians

“…Some studies demonstrated that the presence of FVHs was associated with severe clinical impairments and poor functional outcomes, ( Girot et al, 2007 ; Kufner et al, 2015 ; Dong et al, 2017 ; Nam et al, 2017 ; Zhu et al, 2020 ; Wang et al, 2021 ) whereas other studies indicated that FVHs were correlated with good collateral flow and favorable outcomes ( Pérez et al, 2012 ; Dong and Nao, 2019 ; Yuan et al, 2019 ; Aoki et al, 2020 ; Jiang et al, 2020b ; Wang et al, 2020 ; Zhou et al, 2020b ; Derraz et al, 2021 ). In addition, some other studies proposed that FVH has different clinical significance under different conditions regarding prognostic meaning other than information regarding arterial occlusion ( Kim et al, 2016 , 2019 ; Liu et al, 2016 ; Sakuta et al, 2016 ; Li et al, 2018 , 2021 ; Jiang et al, 2019 ; Shang et al, 2019 ; Zhou et al, 2020a ). Studies with prediction of FVH for functional outcomes are summarized in Tables 1 – 3 .…”

“…The association between FVH and functional outcomes varies with time. Shang et al (2019) reported that the symptom-to-imaging time might be an important factor when assessing the prognostic value of FVH. FVH is associated with unfavorable outcomes within 6 h to 14 days after onset, whereas a wider distribution of distal FVH may be favorable beyond 14 days after onset in infarction of the MCA.…”

FLAIR vascular hyperintensity combined with asymmetrical prominent veins in acute anterior circulation ischemic stroke: prediction of collateral circulation and clinical outcome

“…Currently, research on the relationship between FVH and functional outcomes varies with time. The duration of time from symptom onset to imaging has been reported as an essential factor for evaluating the prognostic value of FVH [ 32 ]. In most studies that suggested a correlation between FVH and favorable outcomes, the time from symptom onset to imaging was less than 6 h [ 33 – 35 ].…”

Factors associated with functional disability in patients with acute stroke excluded from alteplase administration due to minor non-disabling neurological deficits

“…In our study, although FLAIR-HAs were not significant in the multivariate analysis, they were a significant predictor of poor functional outcomes in the univariate analysis. The FLAIR-HAs result from retrograde flow through the collateral arterial circulation and are related to the presence of large vessel stenosis or occlusion ( 22 ). The results of our study suggested that patients with large vessel occlusive disease should be considered as candidates for IV alteplase treatment even though presenting as minor stroke, and the LAD patient group should be defined into detailed subclassification according to various imaging parameters, such as the ratio of the penumbra to the infarct core in perfusion imaging studies, FLAIR-HAs in MR images, or diffusion–perfusion mismatch ratios.…”