Abstract P348: Perfusion Collateral Index vs. Hypoperfusion Intensity Ratio in Assessment of Angiographic Collateral Scores in Patients With Acute Ischemic Stroke

Background and Purpose: In acute ischemic stroke (AIS), perfusion imaging, while not directly visualizing collateral vessels, can provide important insight into collateral robustness, indexed by perfusion lesion volume and by perfusion lesion heterogeneity. Two proposed perfusion lesion heterogeneity measures indexing collateral status are the Perfusion Collateral Index (PCI) and Hypoperfusion Intensity Ratio (HIR), but their accuracy compared with direct collateral assessment on DSA has been incompletely characterized. Methods: Consecutive AIS patients with anterior circulation large vessel occlusion who underwent pre-endovascular thrombectomy MRI perfusion imaging were included. MRI measures analyzed were: 1) Perfusion Collateral Index ( PCI) - the volume of moderately hypoperfused tissue (arterial tissue delay time between 2 and 6 seconds: ATD 2-6sec ) multiplied by its corresponding relative cerebral blood volume using Olea software; 2) Hypoperfusion Intensity Ratio (HIR) ratio of moderate TMax >6 s lesion volume versus severe Tmax >10 s lesion volume with the RAPID software program. DSA collateral scores were evaluated by ASITN grading and dichotomized to inadequate (ASTIN <2) vs. adequate (ASTIN ≥3). Results: Among 48 patients meeting entry criteria, age (mean ± SD) was 70 (± 15.2), 54% were female, and NIHSS (median, IQR) was 15 (10-19). For HIR, there was no significant difference in score values in patients with adequate vs inadequate collaterals: 0.35 ± 0.20 vs 0.39 ± 0.25, p=0.68. ROC analysis using previously described cut-off of 0.4 resulted in an AUC of 0.52 and sensitivity/specificity of 71% / 33%. For PCI, score values were significantly higher in patients with adequate vs inadequate collaterals, 117 ± 61 vs. 57 ± 41, p=0.002. ROC analysis using previously described cut-off of 62 resulted in an AUC of 0.8 and sensitivity/specificity of 84% / 78%. Conclusion: Collateral status can be accurately assessed on perfusion MRI with the Perfusion Collateral Index, which outperformed the Hypoperfusion Intensity Ratio. MRI-PCI is an informative imaging biomarker of collateral status in patients with AIS.

Download Full-text

Abstract W P32: Association of Low Cerebral Blood Volume With Negative FLAIR Hyperintensity in Acute Ischemic Stroke

Stroke ◽

10.1161/str.45.suppl_1.wp32 ◽

2014 ◽

Vol 45 (suppl_1) ◽

Author(s):

Nandakumar Nagaraja ◽

Marie Luby ◽

Matthew Edwardson ◽

Ramin Zand ◽

Lawrence L Latour

Keyword(s):

Ischemic Stroke ◽

Acute Ischemic Stroke ◽

Blood Volume ◽

Early Phase ◽

Cerebral Blood Volume ◽

Time Window ◽

Linear Regression Analysis ◽

Onset Time ◽

Stroke Onset ◽

Imaging Biomarker

Objective: FLAIR hyperintensity is being used in clinical trials as a surrogate imaging biomarker for stroke onset time to test the safety of thrombolysis. Studies have shown that patients with negative and positive FLAIR hyperintensity overlap at similar time points from stroke onset in the early phase of acute ischemic stroke (AIS). Hyperintensity on FLAIR MRI likely represents increased tissue water content. We sought to determine if cerebral blood volume (CBV) mediates FLAIR hyperintensity in the early phase of AIS. Methods: AIS patients seen in 2012 were included in the study if i) onset time was known, ii) an MRI with perfusion was performed within 12 hours of onset time, iii) had imaging confirmed vascular occlusion of ICA, M1, or M2. Following co-registration of raw perfusion images with FLAIR, CBV maps were generated using PMA ASIST™ software. Two raters blinded to clinical information separately evaluated the DWI, FLAIR and CBV maps and measured the signal intensity ratio (SIR) for the brightest region on FLAIR normalized by homologous contra-lateral tissue. The SIR was similarly measured for CBV in same region. FLAIR negative was defined as SIR<1.15, “Low CBV” was defined as CBV SIR <0.5. Results: One hundred eighty two patients were screened and 30 met all study criteria; 21 women, with mean age of 71 (± 16) years and median NIHSS 18 (IQR 9-22). Using linear regression analysis, CBV SIR was associated with FLAIR SIR (p <0.049). In the 0-3hr time window, overall CBV was not associated with FLAIR hyperintensity. However, in the 3-7.5hr time window, patients with negative FLAIR were more likely to have low CBV and conversely, patients with positive FLAIR were more likely to have normal CBV. Conclusion: CBV likely mediates FLAIR hyperintensity in 3-7.5hr of stroke onset but it has less impact on FLAIR hyperintensity in the first 3 hours of AIS. Low CBV could be a potential surrogate imaging biomarker in addition to FLAIR hyperintensity in the early phase of AIS.

Download Full-text

Abstract 177: Risk of Thrombolysis-induced Hemorrhagic Transformation in Patients with Acute Ischemic Stroke: A Predictive Model Using Combined MR Perfusion Biomarkers

Stroke ◽

10.1161/str.46.suppl_1.177 ◽

2015 ◽

Vol 46 (suppl_1) ◽

Author(s):

Kambiz Nael ◽

Adam H Bauer ◽

Chelsea S Kidwell

Keyword(s):

Ischemic Stroke ◽

Acute Ischemic Stroke ◽

Roc Analysis ◽

Cerebral Blood Volume ◽

Optimal Parameter ◽

Infarct Volume ◽

Probabilistic Method ◽

Hemorrhagic Transformation ◽

Mr Perfusion ◽

Multivariable Logistic Regression Model

Purpose: Hemorrhagic transformation (HT) is a potential devastating complication of thrombolysis in patients with acute ischemic stroke (AIS). The purpose of this study was to evaluate the predictive role of MR perfusion biomarkers including increased microvascular permeability (K2) and decreased cerebral blood volume (CBV) in the infarction core to predict the risk of HT in a cohort of patients with AIS who received thrombolysis. Methods: In this retrospective study, patients were included if they: had AIS, received thrombolysis, had pre-treatment MRI (including diffusion and perfusion) and had follow-up MRI for evaluation of HT within 7 days. MR perfusion data were processed employing a Bayesian probabilistic method. Using coregistered images, voxel-based K2 and rCBV values were obtained in the region of infarction (defined by ADC < 600 10 –6 mm 2 /s) and compared in patients with and without HT. Receiver operating characteristic (ROC) analysis was performed to determine the optimal parameter/s and threshold for predicting HT. Results: Forty-eight patients met study criteria: mean (SD) age was 67.5 ± 15, median baseline NIHSS was 9 (IQR: 5-24) and mean infarct volume of 34 ± 18 ml (range 11-78 ml). Thirty percent of patients (14/48) had HT. The mean K2 value was significantly ( p< . 0001) higher in patients with HT (0.24 ± 0.17) versus patients without HT (0.08 ± 0.03). Mean rCBV was significantly ( p=0 .0001) lower in patients with HT (0.21 ± 0.02) compared to patients without HT (1.28 ± 0.66). ROC analysis showed a threshold and corresponding sensitivity/specificity of 0.104, 94%/84% for K2 and 0.38, 94/97% for rCBV. The combination of K2 and rCBV resulted in a higher discriminative power with an AUC of 0.97, sensitivity of 94% and specificity of 100%. In a multivariable logistic regression model that included NIHSS and infarct volume, the combined K2-rCBV classifier was an independent predictor of HT. Conclusion: Combined increased permeability and decreased CBV derived from MR perfusion have improved sensitivity and specificity, compared to either measure alone, for prediction of HT following thrombolysis. A larger clinical study is required to validate our results in an independent cohort.

Download Full-text

Abstract TP245: Prediction of Hemorrhagic Transformation in Patients With Acute Ischaemic Stroke and Atrial Fibrillation With Ct Perfusion Aspects Scores

Stroke ◽

10.1161/str.48.suppl_1.tp245 ◽

2017 ◽

Vol 48 (suppl_1) ◽

Author(s):

Qiaoshu Wang ◽

Yanyan Cao ◽

Yongbo Zhao ◽

Louis Caplan

Keyword(s):

Atrial Fibrillation ◽

Ischemic Stroke ◽

Acute Stroke ◽

Acute Ischemic Stroke ◽

Roc Analysis ◽

Cerebral Blood Volume ◽

Ct Perfusion ◽

Mean Transit Time ◽

Operating Characteristics ◽

Middle Cerebral Artery Infarction

Background and Purpose: Hemorrhage transformation (HT) is common in patients with acute cerebral infarction caused by atrial fibrillation. The prediction of HT is crucial after acute stroke, especially for the patients received vessel recanalization therapy. The Alberta Stroke program early CT score (ASPECTS) is used to estimate early ischemic changes within the MCA territory in the acute stroke setting. Several studies indicated that CT perfusion (CTP) and MR diffusion weighted imaging (DWI) ASPECTS scores was useful to quantify the degree of ischemic brain tissue. Hereby we did the study to explore the association of CT perfusion ASPECTS scores with HT in patients with acute ischemic stroke and atrial fibrillation. Methods: This was a single center retrospective study. All patients with middle cerebral artery infarction and atrial fibrillation from September 2008 to September 2013 were included. MR imaging including DWI and gradient echo sequence (GRE), and CTP were required to identify the HT and determine the scores of CTP- ASPECTS. Demographic and clinical characteristics of the HT positive and negative groups were explored. Results: Fifty-four patients were analyzed, among them twenty-four patients (44%) developed HT. According to logistic regression analysis, mean transit time (MTT), cerebral blood volume (CBV) and DWI-ASPECTS scores were associated with HT ( p = 0.035, 0.044, and 0.020 respectively). The following receiver operating characteristics (ROC) analysis revealed area under the curve of MTT, CBV, CBF and DWI were 0.588, 0.737, 0.687, and 0.841 respectively. CBV-ASPECTS score was found to have medium prediction value of HT among all CTP-ASPECTS parameters. ROC analysis also indicated that CBV-ASPECTS score < 7 was the optimal threshold. Conclusions: CTP-ASPECTS was useful to predict the HT of acute ischemic stroke caused by atrial fibrillation and CBV-ASPECTS score < 7 was the preferable parameter.

Download Full-text

Abstract T MP4: Quality of CT Perfusion Imaging Thresholds for Infarct and Penumbra in the Acute Ischemic Stroke Setting: An Updated Systematic Review

Stroke ◽

10.1161/str.46.suppl_1.tmp4 ◽

2015 ◽

Vol 46 (suppl_1) ◽

Author(s):

Christopher d'Esterre ◽

Jonathan Dykeman ◽

Mohamed Al-mekhlafi ◽

Petra Cimflova ◽

Shivanand Patil ◽

...

Keyword(s):

Systematic Review ◽

At Risk ◽

Ischemic Stroke ◽

Acute Ischemic Stroke ◽

Perfusion Imaging ◽

Cerebral Blood Volume ◽

Ct Perfusion ◽

Mean Transit Time ◽

Infarct Core ◽

Not At Risk

Background: CT Perfusion (CTP) may inform treatment decisions in acute ischemic stroke (AIS). We sought to determine extent of variability with CTP thresholds for infarct core and penumbra and reasons for such variability using an up-to-date systematic review. Methods: Search strategy combined the themes of AIS, perfusion imaging, and CT/MRI. Two independent reviewers screened at all levels; disagreements were settled through consensus. Inclusion criteria were CTP within 24hrs of stroke onset and reported perfusion thresholds for infarct core, penumbra, and/or normal/not at risk tissue for mixed grey/white matter. Study demographics, QUADAS assessment of quality, and mean thresholds of cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), relative CBV (rCBV), relative CBF (rCBF), and relative MTT (rMTT) were collected. Thresholds were reported as median mean threshold (interquartile range). Results: The search resulted in a total of 11919 abstracts from EMBASE and MEDLINE. Of these, 711 studies were identified for full-text review, 134 met all eligibility criteria. 29 studies provided thresholds for CTP and were included in the review. For CBF, median mean threshold was 8.64 (7.94-13.92) ml/min/100g for core, 19.1 (17.1-31.9) ml/min/100g for penumbra and 47.4 (35.6-59.1) ml/min/100g for normal/not at risk tissue. For CBV, median mean threshold was 1.0 (0.68-1.88) ml/100g for core, 2.45 (2.0-3.0) ml/100g for penumbra, and 2.65 (2.0-3.3) ml/100g for normal/not at risk tissue. For MTT median mean threshold was 15.6 (15.3-17.7) seconds for core, 10.5 (7.1-46.2) seconds for penumbra, and 3.9 (3.65-4.15) seconds for normal/not at risk tissue. Median mean threshold for rCBF was 29% (22.5%-35.5%) for core. Sufficient TTP and Tmax data were not reported. Overall, quality was highly variable according QUADAS ranging from 20.7% to 93.1% across the 14 variables. Conclusions: Due to heterogeneity of vendor CTP algorithms, follow-up imaging to define infarct core (NCCT, DWI), unknown recanalization times/reperfusion status and differing onset to CT times, CTP thresholds for infarct core and penumbra are highly variable. As such, a single best threshold for core could not be derived from literature.

Download Full-text

Can SCUBE1 be used to predict the early diagnosis, lesion volume and prognosis of acute ischemic stroke?

Turkish Journal of Biochemistry ◽

10.1515/tjb-2018-0040 ◽

2018 ◽

Vol 44 (1) ◽

pp. 16-24

Author(s):

Asli Bolayir ◽

Seyda Figul Gokce ◽

Burhanettin Cigdem ◽

Hasan Ata Bolayir ◽

Aydin Gulunay ◽

...

Keyword(s):

Ischemic Stroke ◽

Early Diagnosis ◽

Acute Ischemic Stroke ◽

Roc Analysis ◽

High Sensitivity ◽

Control Group ◽

Lesion Volume ◽

Epidermal Growth ◽

Independent Effects ◽

Prediction Of Prognosis

Abstract Objective SCUBE1 [signal peptide-CUB (complement C1r/C1 s)-EGF (epidermal growth factor)-like domain-containing protein 1] is a novel biochemical marker. SCUBE1 is thought to play roles both in platelet activation and inflammation, which are important stages for the development of acute ischemic stroke (AIS).The purpose of our study was to determine the diagnostic and prognostic values and temporal change of plasma SCUBE1 levels in AIS patients. Materials and methods Thirty-five patients diagnosed with AIS at the Cumhuriyet University Faculty of Medicine Neurology Department, between June and December 2017, and a control group of 35 healthy volunteers were included. Results Median first day SCUBE1 value in the patient group was 97.51 ng/mL, and the median 7th day SCUBE1 value was 32.72 ng/mL. Median control group SCUBE1 value was 27.51 ng/mL. The first day SCUBE1 levels were significantly higher than the 7th day and the control group SCUBE1 levels (p=0.001, p<0.001, respectively). The ROC analysis showed that SCUBE1 levels above 68.8 ng/mL can be used as an indicator with high sensitivity and specificity for AIS diagnosis. Multivariate analysis revealed that the first day SCUBE1 had significant independent effects on development of AIS. In correlation analysis, plasma SCUBE1 levels showed a significantly positive correlation with lesion volume, NIHSS and MRS values (p<0.01). Conclusion First day plasma SCUBE1 values in AIS patients rised at significant levels compared to the control group. SCUBE1 could use both in the early diagnosis and prediction of prognosis and lesion volume of AIS patients.

Download Full-text

Abstract WP304: Real-World Experience with the RAPID Platform to Screen Acute Ischemic Stroke Patients at a U.S. Comprehensive Stroke Center

Stroke ◽

10.1161/str.51.suppl_1.wp304 ◽

2020 ◽

Vol 51 (Suppl_1) ◽

Author(s):

Rami-James Assadi ◽

Julia Henn ◽

Ajlana Varmaz ◽

Peter Panagos ◽

Michelle Miller-Thomas ◽

...

Keyword(s):

Ischemic Stroke ◽

Acute Ischemic Stroke ◽

Real World ◽

Perfusion Imaging ◽

Number Needed To Screen ◽

Significant Difference ◽

Screening Efficiency ◽

Rapid Perfusion ◽

Comprehensive Stroke Center ◽

Stroke Center

Introduction: Mechanical thrombectomy (MT) is an important part of acute ischemic stroke (AIS) treatment. Recent trials of MT beyond the 6-hour window have utilized RAPID perfusion imaging for patient selection. The utility of this method is established in patients with large vessel occlusions (LVO) but screening efficiency in real-world practice remains unknown. We present the experience of a single, large volume, Comprehensive Stroke Center (CSC) utilizing RAPID to screen patients for LVO and MT. Methods: We performed a retrospective analysis of prospectively collected consecutive patients who presented to our emergency department (ED) between 01/2018 to 06/2019 with suspected LVO. Protocol was based on 2018 AHA guideline Level IA recommendations and followed DAWN and DEFUSE-3 time and imaging parameters. Patients who underwent RAPID imaging were selected for inclusion. Results: 865 patients met criteria for RAPID perfusion imaging (median age 67, females 52%, outside hospital transfers 29%). Of these, 178 (21% of total) were confirmed to have an LVO (40% ED presentation, 10% inpatient, 50% transfer). For patients presenting to the ED (N=509), 14% had an LVO (median NIHSS 13 [IQR 8-19]), of which 41% underwent MT. Mean CTP core and penumbra volume was 25mL and 100mL respectively. Number needed-to-screen in the ED cohort was 7 to detect LVO and 17 to perform MT. Transfer patients showed no significant difference in LVO detection or MT rates compared to ED patients (56%, p=0.3). Conclusions: In ED-presenting patients at a CSC, the number of RAPID perfusion imaging studies needed to detect an additional case of LVO was 7.1, and to perform an additional MT was 17.4. Current AHA Class IA recommendations for evaluation and treatment of AIS yield a reasonably high rate of LVO detection and subsequent MT in real-world practice. Additional multicenter data will be useful to establish benchmarks and improve screening efficiency.

Download Full-text

Predictive value of time-variant color-coded multiphase CT angiography (mCTA) regarding clinical outcome of acute ischemic stroke: in comparison with conventional mCTA and CT perfusion

Acta Radiologica ◽

10.1177/0284185120981770 ◽

2020 ◽

pp. 028418512098177

Author(s):

Yu Lin ◽

Nannan Kang ◽

Jianghe Kang ◽

Shaomao Lv ◽

Jinan Wang

Keyword(s):

Ischemic Stroke ◽

Acute Ischemic Stroke ◽

Predictive Value ◽

Ct Perfusion ◽

Roc Curves ◽

Multivariate Logistic Regression Model ◽

Infarct Core ◽

Predictive Values ◽

Significant Difference ◽

Core Volume

Background Color-coded multiphase computed tomography angiography (mCTA) can provide time-variant blood flow information of collateral circulation for acute ischemic stroke (AIS). Purpose To compare the predictive values of color-coded mCTA, conventional mCTA, and CT perfusion (CTP) for the clinical outcomes of patients with AIS. Material and Methods Consecutive patients with anterior circulation AIS were retrospectively reviewed at our center. Baseline collateral scores of color-coded mCTA and conventional mCTA were assessed by a 6-point scale. The reliabilities between junior and senior observers were assessed by weighted Kappa coefficients. Receiver operating characteristic (ROC) curves and multivariate logistic regression model were applied to evaluate the predictive capabilities of color-coded mCTA and conventional mCTA scores, and CTP parameters (hypoperfusion and infarct core volume) for a favorable outcome of AIS. Results A total of 138 patients (including 70 cases of good outcomes) were included in our study. Patients with favorable prognoses were correlated with better collateral circulations on both color-coded and conventional mCTA, and smaller hypoperfusion and infarct core volume (all P < 0.05) on CTP. ROC curves revealed no significant difference between the predictive capability of color-coded and conventional mCTA ( P = 0.427). The predictive value of CTP parameters tended to be inferior to that of color-coded mCTA score (all P < 0.001). Both junior and senior observers had consistently excellent performances (κ = 0.89) when analyzing color-coded mCTA maps. Conclusion Color-coded mCTA provides prognostic information of patients with AIS equivalent to or better than that of conventional mCTA and CTP. Junior radiologists can reach high diagnostic accuracy when interpreting color-coded mCTA images.

Download Full-text

Efficacy of Mechanical Thrombectomy using Penumbra ACETM Aspiration Catheter Compared to Stent Retriever SolitaireTM FR in Patients with Acute Ischemic Stroke

Brain Sciences ◽

10.3390/brainsci11040504 ◽

2021 ◽

Vol 11 (4) ◽

pp. 504

Author(s):

Dalibor Sila ◽

Markus Lenski ◽

Maria Vojtková ◽

Mustafa Elgharbawy ◽

František Charvát ◽

...

Keyword(s):

Ischemic Stroke ◽

Clinical Outcome ◽

Acute Ischemic Stroke ◽

Clinical Outcomes ◽

Mechanical Thrombectomy ◽

Binary Logistic Regression ◽

Stent Retriever ◽

Good Clinical Outcome ◽

Significant Difference ◽

Aspiration Technique

Background: Mechanical thrombectomy is the standard therapy in patients with acute ischemic stroke (AIS). The primary aim of our study was to compare the procedural efficacy of the direct aspiration technique, using Penumbra ACETM aspiration catheter, and the stent retriever technique, with a SolitaireTM FR stent. Secondarily, we investigated treatment-dependent and treatment-independent factors that predict a good clinical outcome. Methods: We analyzed our series of mechanical thrombectomies using a SolitaireTM FR stent and a Penumbra ACETM catheter. The clinical and radiographic data of 76 patients were retrospectively reviewed. Using binary logistic regression, we looked for the predictors of a good clinical outcome. Results: In the Penumbra ACETM group we achieved significantly higher rates of complete vessel recanalization with lower device passage counts, shorter recanalization times, shorter procedure times and shorter fluoroscopy times (p < 0.001) compared to the SolitaireTM FR group. We observed no significant difference in good clinical outcomes (52.4% vs. 56.4%, p = 0.756). Predictors of a good clinical outcome were lower initial NIHSS scores, pial arterial collateralization on admission head CT angiography scan, shorter recanalization times and device passage counts. Conclusions: The aspiration technique using Penumbra ACETM catheter is comparable to the stent retriever technique with SolitaireTM FR regarding clinical outcomes.

Download Full-text

The anesthetic approach for endovascular recanalization therapy depends on the lesion site in acute ischemic stroke

Neuroradiology ◽

10.1007/s00234-021-02762-3 ◽

2021 ◽

Author(s):

Kilian Fröhlich ◽

Gabriela Siedler ◽

Svenja Stoll ◽

Kosmas Macha ◽

Thomas M. Kinfe ◽

...

Keyword(s):

Ischemic Stroke ◽

Middle Cerebral Artery ◽

Acute Ischemic Stroke ◽

Cerebral Artery ◽

Posterior Circulation ◽

Neurological Deficits ◽

Stroke Severity ◽

Lesion Volume ◽

Middle Cerebral Artery Territory ◽

Cerebral Lesion

Abstract Purpose Endovascular therapy (EVT) of large-vessel occlusion in acute ischemic stroke (AIS) may be performed in general anesthesia (GA) or conscious sedation (CS). We intended to determine the contribution of ischemic cerebral lesion sites on the physician’s decision between GA and CS using voxel-based lesion symptom mapping (VLSM). Methods In a prospective local database, we sought patients with documented AIS and EVT. Age, stroke severity, lesion volume, vigilance, and aphasia scores were compared between EVT patients with GA and CS. The ischemic lesions were analyzed on CT or MRI scans and transformed into stereotaxic space. We determined the lesion overlap and assessed whether GA or CS is associated with specific cerebral lesion sites using the voxel-wise Liebermeister test. Results One hundred seventy-nine patients with AIS and EVT were included in the analysis. The VLSM analysis yielded associations between GA and ischemic lesions in the left hemispheric middle cerebral artery territory and posterior circulation areas. Stroke severity and lesion volume were significantly higher in the GA group. The prevalence of aphasia and aphasia severity was significantly higher and parameters of vigilance lower in the GA group. Conclusions The VLSM analysis showed associations between GA and ischemic lesions in the left hemispheric middle cerebral artery territory and posterior circulation areas including the thalamus that are known to cause neurologic deficits, such as aphasia or compromised vigilance, in AIS-patients with EVT. Our data suggest that higher disability, clinical impairment due to neurological deficits like aphasia, or reduced alertness of affected patients may influence the physician’s decision on using GA in EVT.

Download Full-text