Abstract WP49: Defining the Acute Infarct Core with CT Perfusion in Ischemic Stroke: Physiological and Technical Issues

Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Christopher D d’Esterre ◽  
Enrico Fainardi ◽  
Ting Yim Lee
Keyword(s):  
Optimal Parameter ◽  
Ct Perfusion ◽  
Infarct Volume ◽  
Mean Transit Time ◽  
Reactive Hyperemia ◽  
Poor Correlation ◽  
Infarct Core ◽  
Ischemic Lesion ◽  
Ischemic Time ◽  
Acute Infarct

Background: CT Perfusion (CTP) defined hemodynamic parameters used to delineate admission infarct core can be affected by truncated data acquisition, recanalization status and reactive hyperemia. We determined the optimal CTP parameter for infarct demarcation while taking these variables into account. Methods: 30 patients had CTP/NCCT scanning within 6 hours of ictus, a 24 hour CTA and an NCCT at 3 months post stroke to define final infarct. Patients were analyzed according to: 1) the percent wash out (truncation) of the ischemic time density curve (ITDC) and 2) recanalization status defined using the 24 hour CTA. CTP functional maps were generated using delay insensitive CTP software (GE Healthcare). For all patients, the total ischemic lesion (infarct+penumbra+benign oligemia) was defined using the contrast delay plus mean transit time map. Cerebral blood flow (CBF), cerebral blood volume (CBV) and the product of CBF and CBV (CBFxCBV) were used to define the infarct core defect, according to established thresholds, and compared with the infarct volume defined on the 3 month NCCT. The coefficients of correlation (R2) of linear regression models were used for the comparisons. Results: R2 values for admission CBF, CBV, and CBFxCBV defect versus final infarct volume for patients with and without truncation of the ITDC were 0.89, 0.49, 0.65 and 0.90, 0.42, 0.68, respectively; while R2 values for patients with and without recanalization at 24 hours were 0.73, 0.33, 0.44 and 0.84, 0.54, 0.45, respectively. In addition, for the recanalization group with and without truncation of the ITDC, R2 for CBF, CBV, CBFxCBV versus final infarct volume were 0.73, 0.12, 0.31 and 0.79, 0.58, 0.56, respectively. Hyperemia, defined as an increase in CBV relative to the contralateral hemisphere, was observed in 30% of patients. Both hyperemia and ITDC truncation led to poor correlation between the CBV defect and NCCT defined infarct volume. Conclusion: CBF is the optimal parameter for determining the size of the acute infarct core as it is not affected by truncation of the ITDC and autoregulatory vasodilation causing reactive hyperemia.

scholarly journals CTA Source Images as a Predictor of Final Infarct Volume are Time-Dependent

2010 ◽  
Vol 37 (6) ◽  
pp. 866-867 ◽  
Author(s):  
Dylan Blacquiere ◽  
Miguel Bussière ◽  
Cheemun Lum ◽  
Dar Dowlatshahi
Keyword(s):  
Acute Stroke ◽  
Ct Angiography ◽  
Ct Perfusion ◽  
Infarct Volume ◽  
Artery Occlusion ◽  
Time Dependent ◽  
Infarct Core ◽  
Time Resolved

Avascularity on CT angiography source images (CTASI) may better predict final infarct volume in acute stroke as compared to early ischemic changes on non-contract CT. These CTASI findings may represent infarct core and help determine the extent of salvageable tissue. However, the extent of avascularity on CTASI may overestimate infarct volume if transit of contrast is prolonged due to proximal artery occlusion. We present a case where CT-perfusion (CTP) and time-resolved CT-angiography (CTA) identified salvageable tissue thought to be infarcted on CTASI.

Abstract 38: Brain CT Perfusion is Superior to Non-contrast CT Aspects in the Evaluation of Hyperacute Infarct Volume

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Jelle Demeestere ◽  
Carlos Garcia-Esperon ◽  
Pablo Garcia-Bermejo ◽  
Fouke Ombelet ◽  
Patrick McElduff ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Ischemic Stroke ◽  
Ct Perfusion ◽  
Infarct Volume ◽  
Lesion Volume ◽  
Infarct Core ◽  
Anterior Circulation ◽  
C Statistic ◽  
Contrast Ct ◽  
Core Volume

Objective: To compare the predictive capacity to detect established infarct in acute anterior circulation stroke between the Alberta Stroke Program Early Computed Tomography Score (ASPECTS) on non-contrast computed tomography (CT) and CT perfusion. Methods: Fifty-nine acute anterior circulation ischemic stroke patients received brain non-contrast CT, CT perfusion and hyperacute magnetic resonance imaging (MRI) within 100 minutes from CT imaging. ASPECTS scores were calculated by 4 independent vascular neurologists, blinded from CT perfusion and MRI data. CT perfusion infarct core volumes were calculated by MIStar software. The accuracy of commonly used ASPECTS cut-off scores and a CT perfusion core volume of ≥ 70 mL to detect a hyperacute MRI diffusion lesion of ≥ 70 ml was evaluated. Results: Median ASPECTS score was 9 (IQR 7-10). Median CT perfusion core volume was 22 ml (IQR 10.4-71.9). Median MRI diffusion lesion volume was 24,5 ml (IQR 10-63.9). ASPECTS score of < 6 had a sensitivity of 0.37, specificity of 0.95 and c-statistic of 0.66 to predict an acute MRI lesion ≥ 70 ml. In comparison, a CT perfusion core lesion of ≥ 70 ml had a sensitivity of 0.76, specificity of 0.98 and c-statistic of 0.92. The CT perfusion core lesion covered a median of 100% of the acute MRI lesion volume (IQR 86-100%). Conclusions: CT perfusion is superior to ASPECTS to predict hyperacute MRI lesion volume in ischemic stroke.

Abstract P534: Relationship Between rCBF and Pial Collateral Recruitment in Experimental Acute Ischemic Stroke

Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Niloufar Saadat ◽  
Greg Christoforidis ◽  
Marek Niekrasz ◽  
Steven Roth ◽  
Timothy Carroll
Keyword(s):  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Infarct Volume ◽  
Mean Diffusivity ◽  
Cerebrovascular Reactivity ◽  
Poor Correlation ◽  
P Value ◽  
Infarct Core ◽  
The Core ◽  
Normal Ranges

Purpose: The purpose of this study was to assess the relationship between relative cerebral blood flow (rCBF) by MRI and leptomeningeal collateral recruitment in an experimental acute ischemic stroke model. Methods: This study was approved by the local IACUC. Eight mongrel canines (20-30kg) underwent endovascular middle cerebral artery occlusion (MCAO). Anesthetics were chosen not to interfere with cerebrovascular reactivity. Physiologic parameters were maintained within normal ranges. Pial collateral recruitment was angiographically assessed using a previously published 11-point scale. After the MCAO, subjects underwent DSC and DTI MRI (3T Achieva, Philips Healthcare, Best, Netherlands) in order to derive rCBF and infarct volume by diffusion restriction on mean diffusivity maps. DSC images were imported into Visage software (Visage Imaging; Richmond Australia). The region of interest was drawn on the penumbra and infarct core and corresponding contralateral side. Infarct volume was calculated by using a quantitative voxel-wise threshold by setting a threshold of 1.5 SD relative to normal values based on an ROI drawn to cover the entire contralateral normal hemisphere exclusive of the ventricles. Results: The pial collateral recruitment was strongly correlated with the rCBF on the penumbral region (r 2 = 0.7823, P-value= 0.003), and with the infarct volume measured two hours following occlusion (r 2 = 0.933376, P value= 0.00009.). There was a poor correlation between the pial collateral recruitment and the rCBF ratio on the core region (R 2 =0.4447, p-value= 0.07.) Conclusion: Preliminary data from this study suggests rCBF from the penumbral regions in experimental MCAO has a closer association with pial collateral recruitment relative to rCBF in the core infarct zone. This information has the potential to affect the interpretation of angiographic studies in acute ischemic stroke and underscores the importance of assessing regional differences in rCBF.

Abstract TP49: Irreversible Ischemic Lesion Characterization: Does CBV_ASPECTS Add to CT_ASPECTS?

Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Marina Padroni ◽  
Pilar Coscojuela ◽  
Sandra Boned ◽  
Marc Ribó ◽  
Jordi Cabero ◽  
...  
Keyword(s):  
Acute Stroke ◽  
Symptom Onset ◽  
Cerebral Blood Volume ◽  
Ct Perfusion ◽  
Infarct Volume ◽  
Relevant Information ◽  
Artery Occlusion ◽  
Carotid Artery Occlusion ◽  
Anterior Circulation ◽  
Ischemic Lesion

Introduction: The best technique for selecting acute stroke patients for reperfusion therapies is not defined yet. ASPECTS is a useful score for assessing the extent of early ischemic signs in the anterior circulation on non-contrast CT (CT). Cerebral blood volume (CBV) on CT perfusion (CTP) defines the core lesion assumed to be irreversibly damaged. Whether CBV provides additional information over CT in the initial ASPECTS assessment is unknown. We aim to explore the advantages of CBV_ASPECTS over CT_ASPECTS in the prediction of final infarct volume. Methods: Consecutive patients with middle cerebral or internal carotid artery occlusion who underwent endovascular reperfusion treatment according to initial CT_ASPECTS≥7 were studied. CBV_ASPECTS was assessed blindly later-on. Recanalization was defined as TICI2b3. Final infarct volumes were measured on follow-up imaging. We defined an irrelevant ASPECTS difference (IAD) as: CT_ASPECTS - CBV_ASPECTS≤1. Results: Sixty-five patients, mean age 67±14, median NIHSS:16(10-20) were studied. Recanalization rate was: 78.5%. Median CT_ASPECTS was 9(8-10), and CBV_ASPECTS 8(8-10). Mean time from symptom onset to CT was 219±143 min. 50 patients (76.9%) showed an IAD. The ASPECTS difference was inversely correlated to the time from symptom onset to CT (r:-0.36, p<0.01). A ROC curve defined 120 minutes as the best cut-off time point after which the ASPECTS difference becomes irrelevant. The rate of IAD was significantly higher after 120 minutes (89.5% Vs 37.5; p<0.01). CBV_ASPECTS but not CT_ASPECTS correlated to the final infarct (r:-0.33, p<0.01). However, if CT was done >2 hours after symptom onset, then CT_ASPECTS was correlated to final infarct (r:-0.39, p=0.01). No other variables were associated with CT-CBV_ASPECTS difference. Conclusions: In acute stroke patient CBV_ASPECTS correlates with final infarct volume. However, when CT is performed after 120 minutes from symptoms onset CBV_ASPECTS does not add relevant information to CT_ASPECTS.

Prediction of stroke outcome with echoplanar perfusion- and diffusion-weighted MRI

Neurology ◽  
1998 ◽  
Vol 51 (2) ◽  
pp. 418-426 ◽  
Author(s):  
P. A. Barber ◽  
D. G. Darby ◽  
P. M. Desmond ◽  
Q. Yang ◽  
R. P. Gerraty ◽  
...  
Keyword(s):  
Clinical Outcome ◽  
Perfusion Imaging ◽  
Infarct Volume ◽  
Lesion Size ◽  
Ischemic Lesion ◽  
Magnetic Resonance Perfusion ◽  
Diffusion Weighted ◽  
Acute Infarct ◽  
Stroke Evolution ◽  
And Diffusion

Objectives: We examined the utility of echoplanar magnetic resonance perfusion imaging and diffusion-weighted imaging (DWI) in predicting stroke evolution and outcome in 18 patients with acute hemispheric infarction.Methods: Patients were studied within 24 hours (mean, 12.2 hours), subacutely(mean, 4.7 days), and at outcome (mean, 84 days). Comparisons were made between infarction volumes as measured on perfusion imaging (PI) and isotropic DWI maps, clinical assessment scales (Canadian Neurological Scale, Barthel Index, and Rankin Scale), and final infarct volume (T2-weighted MRI).Results: Acute PI lesion volumes correlated with acute neurologic state, clinical outcome, and final infarct volume. Acute DWI lesions correlated less robustly with acute neurologic state, but correlated well with clinical outcome and final infarct volume. Three of six possible patterns of abnormalities were seen: PI lesion larger than DWI lesion (65%), PI lesion smaller than DWI lesion (12%), and DWI lesion but no PI lesion (23%). A pattern of a PI lesion larger than the DWI lesion predicted DWI expansion into surrounding hypoperfused tissue (p < 0.05). In the other two patterns, DWI lesions did not enlarge, suggesting that no significant increase in ischemic lesion size occurs in the absence of a larger perfusion deficit.Conclusions: Combined early PI and DWI can define different acute infarct patterns, which may allow the selection of rational therapeutic strategies based on the presence or absence of potentially salvageable ischemic tissue.

scholarly journals Evaluation of a CTA-based convolutional neural network for infarct volume prediction in anterior cerebral circulation ischaemic stroke

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Lasse Hokkinen ◽  
Teemu Mäkelä ◽  
Sauli Savolainen ◽  
Marko Kangasniemi
Keyword(s):  
Neural Network ◽  
Thrombolytic Therapy ◽  
Supportive Care ◽  
Convolutional Neural Network ◽  
Ct Perfusion ◽  
Infarct Volume ◽  
University Hospital ◽  
Current Guideline ◽  
Infarct Core

Abstract Background Computed tomography angiography (CTA) imaging is needed in current guideline-based stroke diagnosis, and infarct core size is one factor in guiding treatment decisions. We studied the efficacy of a convolutional neural network (CNN) in final infarct volume prediction from CTA and compared the results to a CT perfusion (CTP)-based commercially available software (RAPID, iSchemaView). Methods We retrospectively selected 83 consecutive stroke cases treated with thrombolytic therapy or receiving supportive care that presented to Helsinki University Hospital between January 2018 and July 2019. We compared CNN-derived ischaemic lesion volumes to final infarct volumes that were manually segmented from follow-up CT and to CTP-RAPID ischaemic core volumes. Results An overall correlation of r = 0.83 was found between CNN outputs and final infarct volumes. The strongest correlation was found in a subgroup of patients that presented more than 9 h of symptom onset (r = 0.90). A good correlation was found between the CNN outputs and CTP-RAPID ischaemic core volumes (r = 0.89) and the CNN was able to classify patients for thrombolytic therapy or supportive care with a 1.00 sensitivity and 0.94 specificity. Conclusions A CTA-based CNN software can provide good infarct core volume estimates as observed in follow-up imaging studies. CNN-derived infarct volumes had a good correlation to CTP-RAPID ischaemic core volumes.

Infarct growth despite full reperfusion in endovascular therapy for acute ischemic stroke

2014 ◽  
Vol 8 (2) ◽  
pp. 117-121 ◽  
Author(s):  
Diogo C Haussen ◽  
Raul G Nogueira ◽  
Mohamed Samy Elhammady ◽  
Dileep R Yavagal ◽  
Mohammad Ali Aziz-Sultan ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Ct Perfusion ◽  
Infarct Volume ◽  
Infarct Core ◽  
Anterior Circulation ◽  
Vessel Occlusion ◽  
Intravenous Tissue Plasminogen Activator ◽  
Stent Retrievers ◽  
Grade 3

AimTo explore the predictors of infarct core expansion despite full reperfusion after intra-arterial therapy (IAT).MethodsWe retrospectively reviewed 604 consecutive patients who underwent IAT for anterior circulation large vessel occlusion acute ischemic stroke in two tertiary centers (2008–2013/2010–2013). Sixty patients selected by MRI or CT perfusion presenting within <24 h of onset with modified Thrombolysis In Cerebral Infarction (mTICI) grade 3 or 2c reperfusion were included. Significant infarct growth (SIG) was defined as infarct expansion >11.6 mL.ResultsMean age was 67.0±13.7 years, 56% were men. Mean National Institute of Health Stroke Scale (NIHSS) score was 16.2±6.1, time from onset to puncture was 6.8±3.1 h, and procedure length was 1.3±0.6 h. MRI was used for baseline core analysis in 43% of patients. Mean baseline infarct volume was 17.1±19.1 mL, absolute infarct growth was 30.6±74.5 mL, and final infarct volume was 47.7±77.7 mL. Overall, 35% of patients had SIG. Three of 21 patients (14%) treated with stent-retrievers had SIG compared with 14 of 39 (36%) with first-generation devices. Eight of 21 patients (38%) with intravenous tissue plasminogen activator (IV t-PA) had infarct growth compared with 25/39 (64%) without. 23% of patients with SIG had a modified Rankin Scale score ≤2 at 3 months compared with 48% of those without SIG. Multivariate logistic regression indicated that race affected infarct growth. Use of IV t-PA (p=0.03) and stent-retrievers (p=0.03) were independently and inversely correlated with SIG.ConclusionsDespite full reperfusion, infarct growth is relatively frequent and may explain poor clinical outcomes in this setting. Ethnicity was found to influence SIG. Use of IV t-PA and stent-retrievers were associated with less infarct core expansion.

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

Stroke ◽  
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.

CT perfusion and angiographic assessment of pial collateral reperfusion in acute ischemic stroke: the CAPRI study

2016 ◽  
Vol 8 (12) ◽  
pp. 1211-1216 ◽  
Author(s):  
Arturo Consoli ◽  
Tommy Andersson ◽  
Ake Holmberg ◽  
Luca Verganti ◽  
Andrea Saletti ◽  
...  
Keyword(s):  
Multivariate Analysis ◽  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Cerebral Blood Volume ◽  
Ct Perfusion ◽  
Mean Transit Time ◽  
Univariate Analysis ◽  
Infarct Core ◽  
Intravenous Tissue Plasminogen Activator ◽  
Dichotomous Variable

BackgroundThe purpose of this study was to evaluate the correlation between a novel angiographic score for collaterals and CT perfusion (CTP) parameters in patients undergoing endovascular treatment for acute ischemic stroke (AIS).Methods103 patients (mean age 66.7±12.7; 48.5% men) with AIS in the anterior circulation territory, imaged with non-contrast CT, CT angiography, and CTP, admitted within 8 h from symptom onset and treated with any endovascular approach, were retrospectively included in the study. Clinical, neuroradiological data, and all time intervals were collected. Careggi Collateral Score (CCS) was used for angiographic assessment of collaterals and the Alberta Stroke Program Early CT Score (ASPECTS) for semiquantitative analysis of CTP maps. Two centralized core laboratories separately reviewed angiographic data, whereas CT findings were evaluated by an expert neuroradiologist. Univariate and multivariate analysis were performed considering CCS both as an ordinal and a dichotomous variable.Results37/103 patients (35.9%) received intravenous tissue plasminogen activator. Median (IQR) ASPECTS was 9 (6–10) for admission CT, 9 (5–10) for cerebral blood volume (CBV) maps, 3 (2–3) for mean transit time maps, 3 (2–4), for cerebral blood flow maps, and 5 (3–7) for CTP mismatch. Univariate analysis showed a significant correlation between CCS and ASPECTS for all CTP parameters. Multivariate analysis confirmed an independent association only between CCS and CBV (p=0.020 when CCS was considered as a dichotomous variable, p=0.026 with ordinal CCS).ConclusionsA correlation between angiographic assessment of the collateral circulation and CTP seems to be present, suggesting that CCS may provide an indirect evaluation of the infarct core volume to consider for patient selection in AIS.

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