Collateral estimation by susceptibility-weighted imaging and prediction of functional outcomes after acute anterior circulation ischemic stroke

The collateral map: prediction of lesion growth and penumbra after acute anterior circulation ischemic stroke

OBJECTIVES

This study evaluated the collateral map's ability to predict lesion growth and penumbra after acute anterior circulation ischemic strokes.

METHODS

This was a retrospective analysis of selected data from a prospectively collected database. The lesion growth ratio was the ratio of the follow-up lesion volume to the baseline lesion volume on diffusion-weighted imaging (DWI). The time-to-maximum (Tmax)/DWI ratio was the ratio of the baseline Tmax  > 6 s volume to the baseline lesion volume. The collateral ratio was the ratio of the hypoperfused lesion volume of the phase_FU (phase with the hypoperfused lesions most approximate to the follow-up DWI lesion) to the hypoperfused lesion volume of the phase_baseline of the collateral map. Multiple logistic regression analyses were conducted to identify independent predictors of lesion growth. The concordance correlation coefficients of Tmax/DWI ratio and collateral ratio for lesion growth ratio were analyzed.

RESULTS

Fifty-two patients, including twenty-six males (mean age, 74 years), were included. Intermediate (OR, 1234.5; p < 0.001) and poor collateral perfusion grades (OR, 664.7; p = 0.006) were independently associated with lesion growth. Phase_FUs were immediately preceded phases of the phase_baselines in intermediate or poor collateral perfusion grades. The concordance correlation coefficients of the Tmax/DWI ratio and collateral ratio for the lesion growth ratio were 0.28 (95% CI, 0.17-0.38) and 0.88 (95% CI, 0.82-0.92), respectively.

CONCLUSION

Precise prediction of lesion growth and penumbra can be possible using collateral maps, allowing for personalized application of recanalization treatments. Further studies are needed to generalize the findings of this study.

CLINICAL RELEVANCE STATEMENT

Precise prediction of lesion growth and penumbra can be possible using collateral maps, allowing for personalized application of recanalization treatments.

KEY POINTS

• Cell viability in cerebral ischemia due to proximal arterial steno-occlusion mainly depends on the collateral circulation. • The collateral map shows salvageable brain extent, which can survive by recanalization treatments after acute anterior circulation ischemic stroke. • Precise estimation of salvageable brain makes it possible to make patient-specific treatment decision.

Impact of Collateral Circulation on Futile Endovascular Thrombectomy in Acute Anterior Circulation Ischemic Stroke

OBJECTIVE

Collateral circulation is associated with the differential treatment effect of endovascular thrombectomy (EVT) in acute ischemic stroke. We aimed to verify the ability of the collateral map to predict futile EVT in patients with acute anterior circulation ischemic stroke.

METHODS

This secondary analysis of a prospective observational study included data from participants underwent EVT for acute ischemic stroke due to occlusion of the internal carotid artery and/or the middle cerebral artery within 8 hours of symptom onset. Multiple logistic regression analyses were conducted to identify independent predictors of futile recanalization (modified Rankin scale score at 90 days of 4-6 despite of successful reperfusion).

RESULTS

In a total of 214 participants, older age (odds ratio [OR], 2.40; 95% confidence interval [CI], 1.56 to 3.67; p<0.001), higher baseline National Institutes of Health Stroke Scale (NIHSS) scores (OR, 1.12; 95% CI, 1.04 to 1.21; p=0.004), very poor collateral perfusion grade (OR, 35.09; 95% CI, 3.50 to 351.33; p=0.002), longer door-to-puncture time (OR, 1.08; 95% CI, 1.02 to 1.14; p=0.009), and failed reperfusion (OR, 3.73; 95% CI, 1.30 to 10.76; p=0.015) were associated with unfavorable functional outcomes. In 184 participants who achieved successful reperfusion, older age (OR, 2.30; 95% CI, 1.44 to 3.67; p<0.001), higher baseline NIHSS scores (OR, 1.12; 95% CI, 1.03 to 1.22; p=0.006), very poor collateral perfusion grade (OR, 4.96; 95% CI, 1.42 to 17.37; p=0.012), and longer door-to-reperfusion time (OR, 1.09; 95% CI, 1.03 to 1.15; p=0.003) were associated with unfavorable functional outcomes.

CONCLUSION

The assessment of collateral perfusion status using the collateral map can predict futile EVT, which may help select ineligible patients for EVT, thereby potentially reducing the rate of futile EVT.

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

BACKGROUND

To investigate the value of fluid-attenuated inversion recovery vascular hyperintensity (FVH) within asymmetrical prominent veins sign (APVS) on susceptibility-weighted imaging predicting collateral circulation and prognosis in patients with acute anterior circulation ischemic stroke.

METHOD

Patients with severe stenosis or occlusion of ICA or MCA M1, who underwent MRI within 72 h from stroke onset were reviewed. The Alberta Stroke Program Early CT Score was used to evaluate the volume of infarction on DWI, the degree of FVH and APVS. Spearman correlation analysis was used to evaluate the correlation between FVH and APVS. All patients were divided into the good prognosis group and the poor prognosis group according to the score of the modified ranking scale (mRS) 90 days after the stroke. Logistic regression analysis was used to explore the relationship between FVH and APVS and functional prognosis, while receiver operating characteristic (ROC) curves were plotted to assess the value of FVH and APVS in predicting prognosis.

RESULTS

Spearman correlation analysis revealed moderate positive correlations between FVH and APVS (r = 0.586, P < 0.001). The poor prognosis group had a higher rate of a history of atrial fibrillation, a larger cerebral infarction volume, a higher NIHSS score at admission, and a higher FVH and APVS score compared with the good prognosis group (all P < 0.05). A further logistic regression indicated that the NIHSS score, cerebral infarction volume, FVH and APVS were independent risk factors for a poor functional prognosis. In terms of FVH, APVS, alone and their combination for the diagnosis of poor prognosis, the sensitivity, specificity, area under the ROC curve (AUC), and 95% confidence interval (CI) were 86.8%, 83.3%, 0.899 (95% CI 0.830-0.968); 60.5%, 93.7%, 0.818 (95% CI 0.723-0.912); 86.8%, 89.6%, 0.921 (95% CI 0.860-0.981), respectively.

CONCLUSION

The presence of FVH and APVS can provide a comprehensive assessment of collateral circulation from the perspective of veins and arteries, and the correlation between the two is positively correlated. Both of them were independent risk factors for poor prognosis, their combination is complementary and can improve the predictive value.

Deep medullary veins as an important imaging indicator of poor prognosis in acute ischemic stroke: a retrospective cohort survey

Background

The deep medullary veins (DMVs), which constitute a component of the intracerebral venous circulation system and are part of intracerebral reperfusion mechanisms, have been suggested as a novel imaging marker for cerebral white matter hypersignal and cerebral small vessel disease based on their discontinuous and reduced visual representation. However, the correlation between the number and continuity of visible DMVs and the poor prognosis of acute ischemic stroke (AIS) remains undefined. Magnetic susceptibility-weighted imaging was applied in this study to assess the distribution and structural characteristics of DMVs in patients with AIS and to investigate its relationship with the poor prognosis of those with AIS.

Methods

This retrospective study included 90 patients diagnosed with AIS in the middle cerebral artery region by the Neurology Department of Liaoning Provincial People's Hospital. Clinical, laboratory, and cranial magnetic resonance imaging data were collected. After the 3-month follow-up visit, patients were dichotomized into good (0-2 points) and poor (≥3 points) prognosis groups based on the modified Rankin Scale score, and the DMV imaging characteristics were evaluated using a 3-level visual rating scale. The association between DMV and AIS prognosis was determined through Mann-Whitney test and multivariate logistic regression analysis.

Results

In univariate analysis, factors that were statistically significant between the different prognostic groups were DMV score (P=0.007), DMV symmetry (P=0.016), infarct size (P=0.029), and admission National Institutes of Health Stroke Scale (NIHSS) score (P<0.001). DMV score had a positive correlation with NIHSS score, (rs=0.209; P=0.048). Logistic regression analysis showed that the DMV score [odds ratio (OR), 1.356; 95% confidence interval (CI): 1.114-1.650; P=0.002], NIHSS score (OR, 1.280; 95% CI: 1.117-1.466; P<0.001), and fasting glucose (OR, 1.220; 95% CI: 1.023-1.456; P=0.027) were risk factors for poor prognosis in those with AIS.

Conclusions

Discontinuity in DMV visualization was found to be associated with an unfavorable prognosis for patients AIS. The visual assessment of DMV through susceptibility-weighted imaging has the potential to predict AIS prognosis and furnish valuable insights for clinical treatment.

Imaging diagnosis of intracranial atherosclerosis stenosis-related large vessel occlusion before and during endovascular therapy

It is becoming increasingly important to identify the type of stroke, especially the mechanism of occlusion, before and during its treatment. In the case of intracranial atherosclerotic stenosis-related large vessel occlusion, it is necessary to develop a treatment strategy that includes not only mechanical thrombectomy but also adjunctive therapies such as primary or rescue therapy (percutaneous angioplasty, intracranial/carotid stenting, local fibrinolysis) and perioperative antithrombotic therapy. However, in clinical practice we often encounter cases where it is difficult to identify the occlusive mechanism before endovascular treatment because of insufficient information in the minimal circumstances of the hyperacute phase of stroke. Here we focus on the imaging diagnosis before and during treatment of intracranial atherosclerotic stenosis-related large vessel occlusion with in situ thrombotic occlusion as the mechanism of thrombotic occlusion, based on previous reports. We describe the diagnosis of intracranial atherosclerotic stenosis-related large vessel occlusion from the perspectives of "thrombus imaging," "perfusion," and "occlusion margin."

Factors predicting good prognosis of failed intra-arterial thrombectomy cases: A retrospective study

Intra-arterial thrombectomy (IAT) has been increasingly applied in the treatment of acute ischemic stroke (AIS) due to large-vessel occlusion, and many related studies have been published. However, limited studies on the prognosis of failed-IAT patients are available. In this study, factors that can predict a good prognosis in patients with failed IAT were studied. Among patients who visited our hospital between January 2016 and September 2022 and underwent IAT, we retrospectively analyzed those with failed IAT. A univariate analysis was performed on the radiological features, medical histories, and other patient characteristics expected to affect the prognosis, and a multivariate analysis was performed on some of these factors. In univariate analysis, a good collateral channel on susceptibility-weighted imaging (SWI), modified thrombolysis in cerebral infarction (mTICI) 2A recanalization, and the pre-procedural modified Rankin scale (mRS) were statistically significant. In the multivariate analysis, good collateral channels on SWI and computed tomography angiography (CTA) and mTICI 2A recanalization were statistically significant. Factors that can predict a good prognosis in patients with failed IAT include good leptomeningeal collateral channels evaluated by CTA and SWI and mTICI 2A recanalization.

Does the Brush-Sign Reflect Collateral Status and DWI-ASPECTS in Large Vessel Occlusion?

Introduction

The relevance of the brush-sign remained poorly documented in large vessel occlusion (LVO). We aimed to assess the relationship between the brush-sign and collateral status and its potential impact on baseline diffusion-weighted imaging–Alberta Stroke Program Early Computed Tomography Score (DWI-ASPECTS) in acute ischemic stroke (AIS) patients eligible to mechanical thrombectomy (MT).

Methods

Consecutive patients admitted in the Lyon Stroke Center with anterior circulation AIS due to intracranial internal carotid artery (ICA) and/or M1 or M2 segment of the middle cerebral artery (MCA) occlusion eligible for MT were included. The brush-sign was assessed on T2-gradient-echo MRI. Collateral status was assessed on digital subtraction angiography according to the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) score.

Results

In this study, 504 patients were included, among which 171 (33.9%) patients had a brush-sign. Patients with a brush-sign more frequently had a poor collateral status [72 (42.1%) vs. 103 (30.9%); p = 0.017]. In univariable analysis, a DWI-ASPECTS < 7 was associated with a brush sign. Following multivariable analysis, the brush-sign no longer affected DWI-ASPECTS < 7 while the latter remained associated with younger age [odds ratio (OR) 0.97, 95% CI.96–0.99], male sex (OR 1.79, 95% CI 1.08–2.99), a higher National Institutes of Health Stroke Scale (NIHSS) score (OR 1.16, 95% CI 1.1–1.21), a poor collateral status (OR 9.35, 95% CI 5.59-16.02), MCA segment (OR 2.54, 95% CI 1.25–5.38), and intracranial ICA (OR 3.01, 95% CI 1.16–8) occlusion.

Conclusions and Relevance

The brush-sign may be a marker of poor collateral status but did not independently predict a lower DWI-ASPECTS.

Clinical Trial Registration

ClinicalTrials.gov, identifier: NCT04620642.

Imaging in Acute Anterior Circulation Ischemic Stroke: Current and Future

Clinical trials on acute ischemic stroke have demonstrated the clinical effectiveness of revascularization treatments within an appropriate time window after stroke onset: intravenous thrombolysis (NINDS and ECASS-III) through the administration of tissue plasminogen activator within a 4.5-hour time window, endovascular thrombectomy (ESCAPE, REVASCAT, SWIFT-PRIME, MR CLEAN, EXTEND-IA) within a 6-hour time window, and extending the treatment time window up to 24 hours for endovascular thrombectomy (DAWN and DEFUSE 3). However, a substantial number of patients in these trials were ineligible for revascularization treatment, and treatments of some patients were considerably futile or sometimes dangerous in the clinical trials. Guidelines for the early management of patients with acute ischemic stroke have evolved to accept revascularization treatment as standard and include eligibility criteria for the treatment. Imaging has been crucial in selecting eligible patients for revascularization treatment in guidelines and clinical trials. Stroke specialists should know imaging criteria for revascularization treatment. Stroke imaging studies have demonstrated imaging roles in acute ischemic stroke management as follows: 1) exclusion of hemorrhage and stroke mimic disease, 2) assessment of salvageable brain, 3) localization of the site of vascular occlusion and thrombus, 4) estimation of collateral circulation, and 5) prediction of acute ischemic stroke expecting hemorrhagic transformation. Here, we review imaging methods and criteria to select eligible patients for revascularization treatment in acute anterior circulation stroke, focus on 2019 guidelines from the American Heart Association/American Stroke Association, and discuss the future direction of imaging-based patient selection to improve treatment effects.

Clinical Implications of Prominent Cortical Vessels on Susceptibility-Weighted Imaging in Acute Ischemic Stroke Patients Treated with Recanalization Therapy

Prominent cortical vessels on susceptibility-weighted imaging (PCV–SWI) correlate with poor leptomeningeal collaterals. However, little is known about PCV–SWI in recanalization therapy-treated patients with anterior circulation large vessel occlusions (LVO). We investigated PCV–SWI-based assessment of leptomeningeal collaterals and outcome predictions in 100 such patients in an observational study. We assessed PCV–SWI using the Alberta Stroke Program Early CT Score and evaluated leptomeningeal collaterals on multiphase CT angiography (mCTA). Predictive abilities were analyzed using multivariable logistic regression and area of receiver operating curves (AUCs). The extent of PCV–SWI correlated with leptomeningeal collaterals on mCTA (Spearman test, r = 0.77; p < 0.001); their presence was associated with worse functional outcomes and a lower successful recanalization rate (adjusted odds ratios = 0.24 and 0.23, 95% CIs = 0.08–0.65 and 0.08–0.65, respectively). The presence of PCV–SWI predicted outcomes better than good collaterals on mCTA did (C-statistic = 0.84 vs. 0.80; 3-month modified Rankin Scale (mRS) 0–2 = 0.75 vs. 0.67 for successful recanalization). Comparison of AUCs showed that they had similar abilities for predicting outcomes (p = 0.68 for 3-month mRS 0–2; p = 0.23 for successful recanalization). These results suggest that PCV–SWI is a useful feature for assessing leptomeningeal collaterals in acute ischemic stroke patients with anterior circulation LVO and predicting outcomes after recanalization therapy.