Automated CT Perfusion Imaging Versus Non-contrast CT for Ischemic Core Assessment in Large Vessel Occlusion

Introduction: Patient selection for endovascular thrombectomy (EVT) for anterior circulation large vessel occlusion (LVO) strokes in the 6-24-hour time window is dependent on delineating clinical core mismatch (CCM) as defined by DAWN trial criteria. In contrast, patient selection in the early window (0-6 hours) can be performed using ASPECTS on CT head. We aim to determine the prevalence of DAWN-CCM in LVO strokes and the impact of time and ASPECTS. Methods: Retrospective analysis of large vessel occlusion [internal carotid and middle cerebral artery-M1] strokes at a CSC. Consecutive patients who underwent CT perfusion or MRI within 120 minutes of CT head were included in the study (treated and untreated). Ischemic core volume was assessed using RAPID [IschemaView] and ASPECTS using automated ASPECTS [Brainomix]. CCM was defined using DAWN trial criteria [DAWN-CCM: NIHSS ≥10 and core <31 ml, NIHSS ≥20 and core <51 ml]. Results: A total of 116 patients were included. Mean age was 71 ±14 and 62% were females. Mean ischemic core volume and median ASPECTS were 46 ±65 ml and 8 (6-9), respectively. In patients with NIHSS score ≥10 (98), 57% had DAWN-CCM in the 0-24-hour window. Proportion of patients with DAWN-CCM in 6-24-hour window was 70% (6-12 hours), 50% (12-18 hours), and 50% (18-24 hours) [p=0.35]. Proportion of patients with DAWN-CCM by ASPECTS group was 88% (ASPECTS 9-10), 64% (ASPECTS 6-8) and 13% (ASPECTS 0-5) [p=<0.01] (Figure 1). Probability of DAWN-CCM declines by 7% for every 2 hours increase in TLKW to imaging, and by 13% for every 1-point decrease in ASPECTS. Conclusion: Approximately 57% of LVO strokes have clinical core mismatch. LVO strokes with DAWN-CCM decline with increasing time and decreasing ASPECTS. ASPECTS alone may be sufficient to identify patients with DAWN-CCM in a resource limited setting and avoid time consuming advanced imaging.

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Effect of Extended CT Perfusion Acquisition Time on Ischemic Core and Penumbra Volume Estimation in Patients with Acute Ischemic Stroke due to a Large Vessel Occlusion

PLoS ONE ◽

10.1371/journal.pone.0119409 ◽

2015 ◽

Vol 10 (3) ◽

pp. e0119409 ◽

Cited By ~ 11

Author(s):

Jordi Borst ◽

Henk A. Marquering ◽

Ludo F. M. Beenen ◽

Olvert A. Berkhemer ◽

Jan Willem Dankbaar ◽

...

Keyword(s):

Ischemic Stroke ◽

Acute Ischemic Stroke ◽

Ct Perfusion ◽

Volume Estimation ◽

Large Vessel ◽

Acquisition Time ◽

Large Vessel Occlusion ◽

Vessel Occlusion ◽

Ischemic Core

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Non-contrast dual-energy CT virtual ischemia maps accurately estimate ischemic core size in large-vessel occlusive stroke

Scientific Reports ◽

10.1038/s41598-021-85143-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Dylan N. Wolman ◽

Fasco van Ommen ◽

Elizabeth Tong ◽

Frans Kauw ◽

Jan Willem Dankbaar ◽

...

Keyword(s):

Primary Outcome ◽

Ct Perfusion ◽

Primary Outcome Measure ◽

Dual Energy ◽

Large Vessel ◽

Dual Energy Ct ◽

Vessel Occlusion ◽

Ischemic Core ◽

Contrast Ct

AbstractDual-energy CT (DECT) material decomposition techniques may better detect edema within cerebral infarcts than conventional non-contrast CT (NCCT). This study compared if Virtual Ischemia Maps (VIM) derived from non-contrast DECT of patients with acute ischemic stroke due to large-vessel occlusion (AIS-LVO) are superior to NCCT for ischemic core estimation, compared against reference-standard DWI-MRI. Only patients whose baseline ischemic core was most likely to remain stable on follow-up MRI were included, defined as those with excellent post-thrombectomy revascularization or no perfusion mismatch. Twenty-four consecutive AIS-LVO patients with baseline non-contrast DECT, CT perfusion (CTP), and DWI-MRI were analyzed. The primary outcome measure was agreement between volumetric manually segmented VIM, NCCT, and automatically segmented CTP estimates of the ischemic core relative to manually segmented DWI volumes. Volume agreement was assessed using Bland–Altman plots and comparison of CT to DWI volume ratios. DWI volumes were better approximated by VIM than NCCT (VIM/DWI ratio 0.68 ± 0.35 vs. NCCT/DWI ratio 0.34 ± 0.35; P < 0.001) or CTP (CTP/DWI ratio 0.45 ± 0.67; P < 0.001), and VIM best correlated with DWI (rVIM = 0.90; rNCCT = 0.75; rCTP = 0.77; P < 0.001). Bland–Altman analyses indicated significantly greater agreement between DWI and VIM than NCCT core volumes (mean bias 0.60 [95%AI 0.39–0.82] vs. 0.20 [95%AI 0.11–0.30]). We conclude that DECT VIM estimates the ischemic core in AIS-LVO patients more accurately than NCCT.

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Abstract P558: Identification of Embolic Stroke in Patients With Large Vessel Occlusion

Stroke ◽

10.1161/str.52.suppl_1.p558 ◽

2021 ◽

Vol 52 (Suppl_1) ◽

Author(s):

Lan Hong ◽

Longting Lin ◽

Gang Li ◽

Jianhong Yang ◽

Geng Yu ◽

...

Keyword(s):

Perfusion Imaging ◽

Delay Time ◽

Validation Cohort ◽

Embolic Stroke ◽

Large Vessel ◽

Smoking History ◽

Large Vessel Occlusion ◽

Vessel Occlusion ◽

Derivation Cohort ◽

History Of

Objective: To develop a simple and objective score using clinical variables and quantified perfusion measures to identify embolic stroke with large vessel occlusions. Methods: Eligible patients from the Chinese centers participating in the International Stroke Perfusion Imaging Registry were included in this study. Patients were split into a derivation cohort (n=213) and a validation cohort (n=116). A score was developed according to the coefficients of independent predictors of embolic stroke from stepwise logistic regression model in the derivation cohort. The performance of the score was validated by assessing its discrimination and calibration. Additionally, a comparison between the area under curve (AUC) of history of atrial fibrillation (AF) alone and history of AF plus the score was also conducted. Results: The independent predictors of embolic stroke made up the Chinese Embolic Stroke Score (CHESS). There were: age (≥64 years, 1 point), non-smoking history (1 point), non-hypertension history (1 point) , baseline NIH Stroke Scale (≥14, 1 point) and delay time>6s volume/delay time>3s volume on perfusion imaging (≥0.23, 2 points). The AUC of CHESS in the derivation cohort and validation cohort were 0.80 and 0.72 respectively. Calibration tests indicated high agreement between predicted and observed probabilities. The AUC of AF-plus-CHESS compared to history of AF alone was significant (derivation cohort P<0.001; validation cohort P=0.01). Conclusions: In a Chinese population, CHESS reliably and independently identified embolic stroke as the cause of large vessel occlusion.

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Prognostic importance of CT ASPECTS and CT perfusion measures of infarction in anterior emergent large vessel occlusions

Journal of NeuroInterventional Surgery ◽

10.1136/neurintsurg-2018-014461 ◽

2018 ◽

Vol 11 (7) ◽

pp. 670-674 ◽

Cited By ~ 3

Author(s):

Syed Ali Raza ◽

Clara M Barreira ◽

Gabriel M Rodrigues ◽

Michael R Frankel ◽

Diogo C Haussen ◽

...

Keyword(s):

Ct Perfusion ◽

Area Under The Curve ◽

Large Vessel ◽

Anterior Circulation ◽

Vessel Occlusion ◽

Nihss Score ◽

Median Baseline ◽

Ct Head ◽

Prognostic Importance ◽

Contrast Ct

BackgroundAge, neurologic deficits, core volume (CV), and clinical core or radiographic mismatch are considered in selection for endovascular therapy (ET) in anterior circulation emergent large vessel occlusion (aELVO). Semiquantitative CV estimation by Alberta Stroke Programme Early CT Score (CT ASPECTS) and quantitative CV estimation by CT perfusion (CTP) are both used in selection paradigms.ObjectiveTo compare the prognostic value of CTP CV with CT ASPECTS in aELVO.MethodsPatients in an institutional endovascular registry who had aELVO, pre-ET National Institutes of Health Stroke Scale (NIHSS) score, non-contrast CT head and CTP imaging, and prospectively collected 3-month modified Rankin Scale (mRS) score were included. Age- and NIHSS-adjusted models, including either CT ASPECTS or CTP volumes (relative cerebral blood flow <30% of normal tissue, total hypoperfusion, and radiographic mismatch), were compared using receiver operator characteristic analyses.ResultsWe included 508 patients with aELVO (60.8% M1 middle cerebral artery, 34% internal carotid artery, mean age 64.1±15.3 years, median baseline NIHSS score 16 (12–20), median baseline CT ASPECTS 8 (7–9), mean CV 16.7±24.8 mL). Age, pre-ET NIHSS, CT ASPECTS, CV, hypoperfusion, and perfusion imaging mismatch volumes were predictors of good outcome (mRS score 0–2). There were no differences in prognostic accuracies between reference (age, baseline NIHSS, CT ASPECTS; area under the curve (AUC)=0.76) and additional models incorporating combinations of age, NIHSS, and CTP metrics including CV, total hypoperfusion or mismatch volume (AUCs 0.72–0.75). Predicted outcomes from CT ASPECTS or CTP CV-based models had excellent agreement (R2=0.84, p<0.001).ConclusionsIncorporating CTP measures of core or penumbral volume, instead of CT ASPECTS, did not improve prognostication of 3-month outcomes, suggesting prognostic equivalence of CT ASPECTS and CTP CV.

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Epidemiological Surveillance of the Impact of the COVID-19 Pandemic on Stroke Care Using Artificial Intelligence

Stroke ◽

10.1161/strokeaha.120.031960 ◽

2021 ◽

Author(s):

Raul G. Nogueira ◽

Jason M. Davies ◽

Rishi Gupta ◽

Ameer E. Hassan ◽

Thomas Devlin ◽

...

Keyword(s):

Artificial Intelligence ◽

Acute Stroke ◽

Systems Of Care ◽

Ct Perfusion ◽

Stroke Care ◽

Large Vessel ◽

Large Vessel Occlusion ◽

Vessel Occlusion ◽

Number Of Patients ◽

The Impact

Background and Purpose: The degree to which the coronavirus disease 2019 (COVID-19) pandemic has affected systems of care, in particular, those for time-sensitive conditions such as stroke, remains poorly quantified. We sought to evaluate the impact of COVID-19 in the overall screening for acute stroke utilizing a commercial clinical artificial intelligence platform. Methods: Data were derived from the Viz Platform, an artificial intelligence application designed to optimize the workflow of patients with acute stroke. Neuroimaging data on suspected patients with stroke across 97 hospitals in 20 US states were collected in real time and retrospectively analyzed with the number of patients undergoing imaging screening serving as a surrogate for the amount of stroke care. The main outcome measures were the number of computed tomography (CT) angiography, CT perfusion, large vessel occlusions (defined according to the automated software detection), and severe strokes on CT perfusion (defined as those with hypoperfusion volumes >70 mL) normalized as number of patients per day per hospital. Data from the prepandemic (November 4, 2019 to February 29, 2020) and pandemic (March 1 to May 10, 2020) periods were compared at national and state levels. Correlations were made between the inter-period changes in imaging screening, stroke hospitalizations, and thrombectomy procedures using state-specific sampling. Results: A total of 23 223 patients were included. The incidence of large vessel occlusion on CT angiography and severe strokes on CT perfusion were 11.2% (n=2602) and 14.7% (n=1229/8328), respectively. There were significant declines in the overall number of CT angiographies (−22.8%; 1.39–1.07 patients/day per hospital, P <0.001) and CT perfusion (−26.1%; 0.50–0.37 patients/day per hospital, P <0.001) as well as in the incidence of large vessel occlusion (−17.1%; 0.15–0.13 patients/day per hospital, P <0.001) and severe strokes on CT perfusion (−16.7%; 0.12–0.10 patients/day per hospital, P <0.005). The sampled cohort showed similar declines in the rates of large vessel occlusions versus thrombectomy (18.8% versus 19.5%, P =0.9) and comprehensive stroke center hospitalizations (18.8% versus 11.0%, P =0.4). Conclusions: A significant decline in stroke imaging screening has occurred during the COVID-19 pandemic. This analysis underscores the broader application of artificial intelligence neuroimaging platforms for the real-time monitoring of stroke systems of care.

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Abstract TP72: Localization of Large Vessel Occlusion (LVO) Stroke in the Posterior Circulation Based on Perfusion Imaging

Stroke ◽

10.1161/str.51.suppl_1.tp72 ◽

2020 ◽

Vol 51 (Suppl_1) ◽

Author(s):

Carlo W Cereda ◽

Jeremy Heit ◽

Abid Qureshi ◽

Archana Hinduja ◽

Mikayel Grigoryan ◽

...

Keyword(s):

Perfusion Imaging ◽

Primary Outcome Measure ◽

Posterior Circulation ◽

Large Vessel ◽

Large Vessel Occlusion ◽

Rater Agreement ◽

Anterior Circulation ◽

Vessel Occlusion ◽

Intracranial Vessel ◽

Imaging Results

Introduction: The vascular territory of an occluded large intracranial vessel can be reliably identified by CT or MR perfusion imaging. Furthermore, prior studies have shown that perfusion imaging can reliably predict the specific vessel that is occluded in anterior circulation large vessel strokes. We evaluated whether perfusion imaging can predict the specific vessel occlusion (vertebral, basilar, or posterior cerebral) in posterior circulation strokes. Hypothesis: We hypothesized that the occluded vessel could be inferred from the perfusion imaging results in >80% of patients with an acute stroke due to large vessel occlusion in the posterior circulation using the simultaneous CTA or MRA as the gold standard. Furthermore, the inter-rater agreement between a vascular neurologist and a neuroradiologist would be > 90%. Agreement Coefficients (AC1) were determined. Methods: From a multicenter cohort of consecutive patients with posterior circulation stroke, we included patients with documented occlusion of the Basilar Artery (BA) posterior cerebral Artery (PCA) or vertebral artery (VA) who had perfusion imaging (MRI or CT) processed by RAPID software. Perfusion images were evaluated blinded to the angiography or any other brain imaging results. The primary outcome measure was agreement on LVO location based on the CTA/MRA results. Results: 74 patients were eligible: age 63±2, female 32%, median NIHSS 15 (IQR 5-24). The distribution of large vessel occlusions on CTA/MRA was BA (74%), PCA (14%) and VA (12%). Perfusion imaging was able to correctly predict the occluded vessel in 63 (85%), AC1 = 0.82 (95% CI 0.72-0.92), p<0.001. Interrater agreement (n=41) was high [AC1 = 0.94 (95% CI 0.87-1.0), p < 0.001]. Conclusion: Perfusion imaging can predict the site of vessel occlusion (vertebral, basilar, or posterior cerebral) in posterior circulation strokes with good accuracy and high inter-rater agreement.

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Abstract WP290: Endovascular Treatment Of In-hospital Strokes: An Open Book

Stroke ◽

10.1161/str.44.suppl_1.awp290 ◽

2013 ◽

Vol 44 (suppl_1) ◽

Author(s):

Dolora Wisco ◽

KEN UCHINO ◽

ESTEBAN CHENG CHING ◽

Shazia Alam ◽

SHUMEI MAN ◽

...

Keyword(s):

Mechanical Thrombectomy ◽

Patient Characteristics ◽

Large Vessel ◽

Large Vessel Occlusion ◽

Valve Repair ◽

Anterior Circulation ◽

Vessel Occlusion ◽

Ct Brain ◽

Contrast Ct ◽

Iv Tpa

INTRODUCTION: In-hospital stroke (IHS) presents a different treatment challenge than out of hospital stroke. IHS often has contraindication to IV tPA, such as such as recent surgery, MI, and use of anticoagulation. Intra-arterial therapy (IAT) with tPA and/or mechanical thrombectomy is an option for large vessel acute IHS with contraindications to or fail to recanalize with IV tPA, to restore cerebral perfusion. Objective: To assess the characteristics and outcomes of patients with in-hospital strokes large vessel occlusion who receive IAT. Methods: From our database of patients from 1/1/2008 to 12/31/2011 who had IAT for an acute stroke due to large vessel occlusion, in hospital strokes and out of hospital strokes were identified. Patient characteristics, imaging, and outcomes were retrospectively collected. Statistical analysis was performed on JMP 9.0. Result: 151 patients were included, 23 (15%) were in-hospital strokes (IHS) and 128 (85%) were out of hospital strokes (OHS). Initial median NIHSS of 17 and 16 respectively (p=0.3). IHS were frequently in the cardiology/CTS service (14, 60%) for CHF and cardiac valve repair (12, 52%). Other comorbidities present were atrial fibrillation (68%), hypertension (68%), and hyperlipidemia (56%). Seven (30%) were on warfarin prior to admission, but all had subtherapeutic INR. Three (13%) IHS received IV tPA. The time from last known well (LKW) to non-contrast CT brain was 80 min, and to CTA was 113 min in IHS, and 147 min and 229 min respectively in OHS (p = 0.0003). 20 (87%) had lesion in the anterior circulation. LKW to IAT recanalization was 248 min in IHS, compared to 375 min in OHS. Recanalization rate was 68% for IHS and 81% for OHS (p=0.2). Nine (39%) IHS had favorable mRS of 1 to 3 at 90 days, compared to 44 (34%) OHS, (p = 0.6). Despite faster recanalization time, there was no difference in the 90 day mortality of IHS v OHS (48% vs 30%, p = 0.1), and IHS had greater 1 year mortality (65% vs 30%, p = 0.005). Discussion: In-hospital strokes have higher mortality than out of hospital strokes. There is a role for IAT In carefully selected IHS with large vessel occlusion. A multicenter study is needed to reveal the characteristics of IHS patients who may benefit from IAT.

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Abstract WP82: Ghost Infarct Core: Ischemic Oreoverestimation by Admission CT Perfusion on Large Vessel Occlusion Stroke Patients

Stroke ◽

10.1161/str.50.suppl_1.wp82 ◽

2019 ◽

Vol 50 (Suppl_1) ◽

Author(s):

Gabriel M Rodrigues ◽

Michael Frankel ◽

Diogo C Haussen ◽

Raul G Nogueira

Keyword(s):

Ct Perfusion ◽

Large Vessel ◽

Large Vessel Occlusion ◽

Stroke Patients ◽

Infarct Core ◽

Vessel Occlusion

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Initial hospital management of patients with emergent large vessel occlusion (ELVO): report of the standards and guidelines committee of the Society of NeuroInterventional Surgery

Journal of NeuroInterventional Surgery ◽

10.1136/neurintsurg-2015-011984 ◽

2015 ◽

Vol 9 (3) ◽

pp. 316-323 ◽

Cited By ~ 64

Author(s):

Ryan A McTaggart ◽

Sameer A Ansari ◽

Mayank Goyal ◽

Todd A Abruzzo ◽

Barb Albani ◽

...

Keyword(s):

Ct Perfusion ◽

Imaging Techniques ◽

Hospital Management ◽

Clinical Severity ◽

Large Vessel ◽

Stroke Severity ◽

Large Vessel Occlusion ◽

Vessel Occlusion ◽

Initial Hospital ◽

Iv Tpa

ObjectiveTo summarize the current literature regarding the initial hospital management of patients with acute ischemic stroke (AIS) secondary to emergent large vessel occlusion (ELVO), and to offer recommendations designed to decrease the time to endovascular treatment (EVT) for appropriately selected patients with stroke.MethodsUsing guidelines for evidenced-based medicine proposed by the Stroke Council of the American Heart Association, a critical review of all available medical literature supporting best initial medical management of patients with AIS secondary to ELVO was performed. The purpose was to identify processes of care that most expeditiously determine the eligibility of a patient with an acute stroke for interventions including intravenous fibrinolysis with recombinant tissue plasminogen activator (IV tPA) and EVT using mechanical embolectomy.ResultsThis review identifies four elements that are required to achieve timely revascularization in ELVO. (1) In addition to non-contrast CT (NCCT) brain scan, CT angiography should be performed in all patients who meet an institutional threshold for clinical stroke severity. The use of any advanced imaging beyond NCCT should not delay the administration of IV tPA in eligible patients. (2) Activation of the neurointerventional team should occur as soon as possible, based on either confirmation of large vessel occlusion or a prespecified clinical severity threshold. (3) Additional imaging techniques, particularly those intended to physiologically select patients for EVT (CT perfusion and diffusion–perfusion mismatch imaging), may provide additional value, but should not delay EVT. (4) Routine use of general anesthesia during EVT procedures, should be avoided if possible. These workflow recommendations apply to both primary and comprehensive stroke centers and should be tailored to meet the needs of individual institutions.ConclusionsPatients with ELVO are at risk for severe neurologic morbidity and mortality. To achieve the best possible clinical outcomes stroke centers must optimize their triage strategies. Strategies that provide patients with ELVO with the fastest access to reperfusion depend upon detail-oriented process improvement.

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