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Background: Collateral status (CS) is an important biomarker of functional outcomes in patients with acute ischemic stroke secondary to large vessel occlusion (AIS-LVO). Pretreatment CT perfusion (CTP) parameters serve as reliable surrogates of collateral status (CS). In this study, we aim to assess the relationship between the relative cerebral blood flow less than 38% (rCBF <38%), with the reference standard American Society of Interventional and Therapeutic Neuroradiology (ASITN) collateral score (CS) on DSA. Methods: In this prospectively collected, retrospectively reviewed analysis, inclusion criteria were as follows: (a) CT angiography (CTA) confirmed anterior circulation large vessel occlusion from 9/1/2017 to 10/01/2023; (b) diagnostic CT perfusion; and (c) underwent mechanical thrombectomy with documented ASITN CS. The ratios of the CTP-derived CBF values were calculated by dividing the values of the ischemic lesion by the corresponding values of the contralateral normal region (which were defined as rCBF). Spearman's rank correlation and logistic regression analysis were performed to determine the relationship of rCBF <38% lesion volume with DSA ASITN CS. p ≤.05 was considered significant. Results: In total, 223 patients [mean age: 67.77 ± 15.76 years, 56.1% (n = 125) female] met our inclusion criteria. Significant negative correlation was noted between rCBF <38% volume and DSA CS (ρ = −0.37, p <.001). On multivariate logistic regression analysis, rCBF <38% volume was found to be independently associated with worse ASITN CS (unadjusted OR: 3.03, 95% CI: 1.60–5.69, p <.001, and adjusted OR: 2.73, 95% CI: 1.34–5.50, p <.01). Conclusion: Greater volume of tissue with rCBF <38% is independently associated with better DSA CS. rCBF <38% is a useful adjunct tool in collateralization-based prognostication. Future studies are needed to expand our understanding of the role of rCBF <38% within the decision-making in patients with AIS-LVO. [ABSTRACT FROM AUTHOR]

BACKGROUND: Pretreatment CT Perfusion (CTP) parameters serve as reliable surrogates of collateral status (CS). In this study, we aim to assess the relationship between the novel compensation index (CI, Tmax > 4 s/Tmax > 6 s) and already established CTP collateral markers, namely cerebral blood volume (CBV) index and Hypoperfusion Intensity Ratio (HIR), with the reference standard American Society of Interventional and Therapeutic Neuroradiology (ASITN) collateral score (CS) on DSA. METHODS: In this retrospective study, inclusion criteria were the following: (a) CT angiography confirmed anterior circulation large vessel occlusion from 9 January 2017 to 10 January 2023; (b) diagnostic CT perfusion; and (c) underwent mechanical thrombectomy with documented DSA-CS. Student t-test, Mann-Whitney-U-test and Chi-square test were used to assess differences. Spearmans rank correlation and logistic regression analysis were used to assess associations. p ≤ 0.05 was considered significant. RESULTS: In total, 223 patients (mean age: 67.8 ± 15.8, 56% female) met our inclusion criteria. The CI (ρ = 0.37, p < 0.001) and HIR (ρ = -0.29, p < 0.001) significantly correlated with DSA-CS. Whereas the CBV Index (ρ = 0.1, p > 0.05) did not correlate with DSA-CS. On multivariate logistic regression analysis taking into account age, sex, ASPECTS, tPA, premorbid mRS, NIH stroke scale, prior history of TIA, stroke, atrial fibrillation, diabetes mellitus, hyperlipidemia, heart disease and hypertension, only CI was not found to be independently associated with DSA-CS (adjusted OR = 1.387, 95% CI: 1.09-1.77, p < 0.01). CONCLUSION: CI demonstrates a stronger correlation with DSA-CS compared to both the HIR and CBV Index where it may show promise as an additional quantitative pretreatment CS biomarker.

Background and Purpose: Distal medium vessel occlusions (DMVOs) are a significant contributor to acute ischemic stroke (AIS), with collateral status (CS) playing a pivotal role in modulating ischemic damage progression. We aimed to explore baseline characteristics associated with CS in AIS‐DMVO. Methods: This retrospective analysis of a prospectively collected database enrolled 130 AIS‐DMVO patients from two comprehensive stroke centers. Baseline characteristics, including patient demographics, admission National Institutes of Health Stroke Scale (NIHSS) score, admission Los Angeles Motor Scale (LAMS) score, and co‐morbidities, including hypertension, hyperlipidemia, diabetes, coronary artery disease, atrial fibrillation, and history of transient ischemic attack or stroke, were collected. The analysis was dichotomized to good CS, reflected by hypoperfusion index ratio (HIR) <.3, versus poor CS, reflected by HIR ≥.3. Results: Good CS was observed in 34% of the patients. As to the occluded location, 43.8% occurred in proximal M2, 16.9% in mid M2, 35.4% in more distal middle cerebral artery, and 3.8% in distal anterior cerebral artery. In multivariate logistic analysis, a lower NIHSS score and a lower LAMS score were both independently associated with a good CS (odds ratio [OR]: 0.88, 95% confidence interval [CI]: 0.82‐0.95, p <.001 and OR: 0.77, 95% CI: 0.62‐0.96, p =.018, respectively). Patients with poor CS were more likely to manifest as moderate to severe stroke (29.1% vs. 4.5%, p <.001), while patients with good CS had a significantly higher chance of having a minor stroke clinically (40.9% vs. 12.8%, p <.001). Conclusions: CS remains an important determinant in the severity of AIS‐DMVO. Collateral enhancement strategies may be a worthwhile pursuit in AIS‐DMVO patients with more severe initial stroke presentation, which can be swiftly identified by the concise LAMS and serves as a proxy for underlying poor CS. [ABSTRACT FROM AUTHOR]

• After adjusting for age, sex, ASPECTS, tPA, premorbid mRS, admission NIH stroke scale, prior history of TIA, stroke, atrial fibrillation, diabetes mellitus, hyperlipidemia, heart disease and hypertension, admission LAMS was found to be independently associated with CBV Index (adjusted OR:0.82, p < 0.01). • After adjusting for age, sex, ASPECTS, tPA, premorbid mRS, admission NIH stroke scale, prior history of TIA, stroke, atrial fibrillation, diabetes mellitus, hyperlipidemia, heart disease and hypertension, admission LAMS was found to be independently associated with and HIR (adjusted OR:1.70, p < 0.05). • Admission LAMS is independently associated with CTP CS markers, CBV index and HIR. This finding suggests that LAMS may also provide an indirect estimate of CS, among other factors. The Los Angeles Motor Scale (LAMS) is an objective tool that has been used to rapidly assess and predict the presence of large vessel occlusion (LVO) in the pre-hospital setting successfully in several studies. However, studies assessing the relationship between LAMS score and CT perfusion collateral status (CS) markers such as cerebral blood volume (CBV) index, and hypoperfusion intensity ratio (HIR) are sparse. Our study therefore aims to assess the association of admission LAMS score with established CTP CS markers CBV Index and HIR in AIS-LVO cases. In this prospectively collected, retrospectively reviewed analysis, inclusion criteria were as follows: a) CT angiography (CTA) confirmed anterior circulation LVO from 9/1/2017 to 10/01/2023, and b) diagnostic CT perfusion (CTP). Logistic regression analysis was performed to assess the relationship between admission LAMS with CTP CS markers HIR and CBV Index. p ≤ 0.05 was considered significant. In total, 285 consecutive patients (median age = 69 years; 56 % female) met our inclusion criteria. Multivariable logistic regression analysis adjusting for sex, age, ASPECTS, tPA, premorbid mRS, admission NIH stroke scale, prior history of TIA, stroke, atrial fibrillation, diabetes mellitus, hyperlipidemia, coronary artery disease and hypertension, admission LAMS was found to be independently associated with CBV Index (adjusted OR:0.82, p < 0.01), and HIR (adjusted OR:0.59, p < 0.05). LAMS is independently associated with CTP CS markers, CBV index and HIR. This finding suggests that LAMS may also provide an indirect estimate of CS. [ABSTRACT FROM AUTHOR]

The mortality rate of acute intracerebral hemorrhage (ICH) can reach up to 40%. Although the radiomics of ICH have been linked to hematoma expansion and outcomes, no research to date has explored their correlation with mortality. In this study, we determined the admission non-contrast head CT radiomic correlates of survival in supratentorial ICH, using the Antihypertensive Treatment of Acute Cerebral Hemorrhage II (ATACH-II) trial dataset. We extracted 107 original radiomic features from n = 871 admission non-contrast head CT scans. The Cox Proportional Hazards model, Kaplan–Meier Analysis, and logistic regression were used to analyze survival. In our analysis, the "first-order energy" radiomics feature, a metric that quantifies the sum of squared voxel intensities within a region of interest in medical images, emerged as an independent predictor of higher mortality risk (Hazard Ratio of 1.64, p < 0.0001), alongside age, National Institutes of Health Stroke Scale (NIHSS), and baseline International Normalized Ratio (INR). Using a Receiver Operating Characteristic (ROC) analysis, "the first-order energy" was a predictor of mortality at 1-week, 1-month, and 3-month post-ICH (all p < 0.0001), with Area Under the Curves (AUC) of >0.67. Our findings highlight the potential role of admission CT radiomics in predicting ICH survival, specifically, a higher "first-order energy" or very bright hematomas are associated with worse survival outcomes. [ABSTRACT FROM AUTHOR]

Background In acute ischemic stroke (AIS), collateral status (CS) is an important predictor of favorable outcomes in patients with AIS. Among quantitative cerebral perfusion parameters, relative cerebral blood flow (rCBF) is considered an accurate perfusion‐based indicator of CS. This study investigated the relationship between admission laboratory values, baseline characteristics, and CS as assessed by rCBF in patients with AIS‐large vessel occlusion. Methods and Results In this retrospective multicenter study, consecutive patients presenting with AIS secondary to anterior circulation large vessel occlusion who underwent pretreatment computed tomography perfusion were included. The computed tomography perfusion data processed by RAPID (IschemaView, Menlo Park, CA) generated the rCBF. Binary logistic regression models assessed the relationship between patients' baseline characteristics, admission laboratory values, and poor CS. The primary outcome measure was the presence of poor CS, which was defined as rCBF

Background: A major driver of individual variation in long-term outcomes following a large vessel occlusion (LVO) stroke is the degree of collateral arterial circulation. We aimed to develop and evaluate machine-learning models that quantify LVO collateral status using admission computed tomography angiography (CTA) radiomics. Methods: We extracted 1116 radiomic features from the anterior circulation territories from admission CTAs of 600 patients experiencing an acute LVO stroke. We trained and validated multiple machine-learning models for the prediction of collateral status based on consensus from two neuroradiologists as ground truth. Models were first trained to predict (1) good vs. intermediate or poor, or (2) good vs. intermediate or poor collateral status. Then, model predictions were combined to determine a three-tier collateral score (good, intermediate, or poor). We used the receiver operating characteristics area under the curve (AUC) to evaluate prediction accuracy. Results: We included 499 patients in training and 101 in an independent test cohort. The best-performing models achieved an averaged cross-validation AUC of 0.80 ± 0.05 for poor vs. intermediate/good collateral and 0.69 ± 0.05 for good vs. intermediate/poor, and AUC = 0.77 (0.67–0.87) and AUC = 0.78 (0.70–0.90) in the independent test cohort, respectively. The collateral scores predicted by the radiomics model were correlated with (rho = 0.45, p = 0.002) and were independent predictors of 3-month clinical outcome (p = 0.018) in the independent test cohort. Conclusions: Automated tools for the assessment of collateral status from admission CTA—such as the radiomics models described here—can generate clinically relevant and reproducible collateral scores to facilitate a timely treatment triage in patients experiencing an acute LVO stroke. [ABSTRACT FROM AUTHOR]

Background and Purpose: Acute ischemic stroke due to large vessel occlusion (AIS‐LVO) is a major cause of functional dependence. Collateral status (CS) is an important determinant of functional outcomes. Pretreatment CT perfusion (CTP) parameters serve as reliable surrogates of CS. Penumbra Salvage Index (PSI) is another parameter predictive of functional outcomes in AIS‐LVO. The aim of this study is to assess the relationship of pretreatment CTP parameters with PSI. Methods: In this prospectively collected, retrospectively reviewed multicenter analysis, inclusion criteria were as follows: (1) CT angiography confirmed middle cerebral artery (MCA) M1‐segment and proximal M2‐segment occlusion from 9/1/2017 to 9/22/2022; (2) diagnostic CTP; and (3) available diagnostic Magnetic resonance Imaging (MRI) diffusion‐weighted images. Pearson correlation analysis was performed to assess the association between cerebral blood volume (CBV) index and hypoperfusion intensity ratio (HIR) with PSI. p value ≤.05 was considered statistically significant. Results: In total, 131 patients (n = 86, M1 and n = 45, proximal M2 occlusion) met our inclusion criteria. CBV index showed a modest positive correlation with PSI (r = 0.34, p<.001) in patients with proximal MCA occlusion. Similar trends were noted in subgroup analysis of patients with M1 occlusion, and proximal M2 occlusion. Whereas, HIR did not have a strong trend or correlation with PSI. Conclusion: CBV index correlates with PSI, whereas HIR does not. Future studies are needed to expand our understanding of the adjunct role of CBV index with other similar pretreatment CTP‐based markers in clinical evaluation and decision‐making in patients with MCA occlusion. [ABSTRACT FROM AUTHOR]

Xin Jiang,&ast; Lijie Gao,&ast; Jian Wang, Jiajia Bao, Jinghuan Fang, Li He Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Jinghuan Fang; Li He, Department of Neurology, West China Hospital, Sichuan University, No. 37 Guoxue Lane, Chengdu, Sichuan Province, 610041, People’s Republic of China, Email jinghuan_fang@126.com; heli2003new@126.comBackground: Blood pressure variation and collateral status have been reported to be associated with clinical outcome in patients with acute ischemic stroke who received endovascular treatment; however, the relationship between blood pressure variation within 72 hours after EVT and clinical outcome in different collateral status remains unclear.Methods: Acute ischemic stroke patients due to large vessel occlusion with EVT were retrospectively enrolled. We classified participants into poor collateral (ASITN/SIR grade < 2) and good collateral subgroups (ASITN/SIR grade ≥ 2). The primary outcome was unfavorable neurological outcome defined as a 3-month modified Rankin Scale (mRS) score ≥ 2. The interactive effect was tested to determine the influence of collateral status on the association between BP variation and clinical outcome.Results: A total of 545 patients were included. The poor collateral subgroup was detected in 198 patients with an average age of 70.2 years. The association between BP variation and primary outcome did not differ under different collateral status (P for interaction > 0.05). However, the association between the mean and coefficient of variation (CV) values of DBP and 3-month mortality was significantly discrepant under different collateral status (P for interaction < 0.05). In the good collateral subgroup, higher mean DBP was associated with a lower risk of 3-month mortality (OR 0.95, 95% CI 0.91– 1, P = 0.033) compared with the poor subgroup (OR 1.04, 95% CI 0.97– 1.1, P = 0.286). In addition, a higher CV of DBP was associated with a higher risk of 3-month mortality (OR 1.24, 95% CI 1.13– 1.36, P < 0.01) compared with poor status (OR 1.08, 95% CI 0.94– 1.23, P=0.275).Conclusion: For patients who received EVT with good collateral status, increased CV of DBP was significantly associated with higher 3-month mortality, while higher mean DBP within 72 h after EVT was associated with a decrease in 3-month mortality.Keywords: acute ischemic stroke, blood pressure variability, clinical outcome, collateral status, endovascular treatment

The importance of assessing the collateral status (CS) in patients with ischaemic stroke (IS) has repeatedly been emphasised in clinical guidelines. Various publications offer qualitative or semiquantitative scales with gradations corresponding to the different extents of the collaterals, visualised mostly on the basis of CTA images. However, information on their inter-rater reliability is limited. Therefore, the aim of this study is to investigate the inter-rater reliability of the scales for collateral assessment. CTA images of 158 patients in the acute period of IS were used in the study. The assessment of CS was performed by two experts using three methodologies: the modified Tan scale, the Miteff scale, and the Rosenthal scale. Cohen's kappa, weighted kappa and Krippendorff's alpha were used as reliability measures. For the modified Tan scale and the Miteff and Rosenthal scales, the weighted kappa values were 0.72, 0.49 and 0.59, respectively. Although the best measure of consistency was found for the modified Tan scale, no statistically significant differences were revealed among the scales. The impact of the CS on the degree of neurological deficit at discharge was shown for the modified Tan and Rosenthal scales. In conclusion, the analysis showed a moderate inter-rater reliability of the three scales, but was not able to distinguish the best one among them. [ABSTRACT FROM AUTHOR]

目的 评估急性前循环大血管闭塞性脑梗死接受血管内治疗患者的侧支循环状态对3个月的临床结局的影响，分析无效再通的危险因素。 方法 本研究基于急性缺血性卒中（acute ischemic stroke，AIS）再通后重症监护的登记研究（registration study for critical care of acute ischemic stroke after recanalization，RESCUE-RE）数据库，根据美国介入和治疗神经放射学协会/介入放射学协会制定的基于DSA的侧支分级方法，将符合入组标准的血管内血栓切除术（endovascular thrombectomy，EVT）成功再通的AIS患者分为侧支不良（0～1级）和侧支良好（2～4级）两组。无效再通定义为血管内治疗术后成功再通（mTICI分级≥2b级），但患者术后90 d功能预后不良（mRS评分≥3分）。比较侧支不良组和侧支良好组基线特点和预后结局的差异，采用多因素logistic回归分析侧支状态对无效再通的影响。 结果 本研究共纳入748例EVT后成功再通的急性前循环大血管闭塞性脑梗死患者，其中侧支不良组323例（43.2%），374例（50.0%）发生无效再通。一般资料显示，侧支不良组合并心房颤动（27.6% vs. 18.4%，P=0.003）、糖尿病病史（26.9% vs. 16.0%，P

Background: Collateral status is an important predictor for the outcome of acute ischemic stroke with large vessel occlusion. Multiphase computed-tomography angiography (mCTA) is useful to evaluate the collateral status, but visual evaluation of this examination is time-consuming. This study aims to use an artificial intelligence (AI) technique to develop an automatic AI prediction model for the collateral status of mCTA. Methods: This retrospective study enrolled subjects with acute ischemic stroke receiving endovascular thrombectomy between January 2015 and June 2020 in a tertiary referral hospital. The demographic data and images of mCTA were collected. The collateral status of all mCTA was visually evaluated. Images at the basal ganglion and supraganglion levels of mCTA were selected to produce AI models using the convolutional neural network (CNN) technique to automatically predict the collateral status of mCTA. Results: A total of 82 subjects were enrolled. There were 57 cases randomly selected for the training group and 25 cases for the validation group. In the training group, there were 40 cases with a positive collateral result (good or intermediate) and 17 cases with a negative collateral result (poor). In the validation group, there were 21 cases with a positive collateral result and 4 cases with a negative collateral result. During training for the CNN prediction model, the accuracy of the training group could reach 0.999 ± 0.015, whereas the prediction model had a performance of 0.746 ± 0.008 accuracy on the validation group. The area under the ROC curve was 0.7. Conclusions: This study suggests that the application of the AI model derived from mCTA images to automatically evaluate the collateral status is feasible.

Abstract Background Mechanical thrombectomy (MT) has been proven as an effective and safe therapy for patients with acute ischemic stroke from large vessel occlusion. However, there is still a controversial topic about post-procedural management including blood pressure (BP). Methods A total of 294 patients who received MT in Second Affiliated Hospital of Soochow University from April 2017 to September 2021 were included consecutively. The association of blood pressure parameters (BPV and hypotension time) with poor functional outcome was evaluated using logistic regression models. Meanwhile, the effects of BP parameters on mortality was analyzed using cox proportional hazards regression models. Furthermore, the corresponding multiplicative term was added to the above models to study the interaction between BP parameters and CS. Results Two hundred ninety four patients were included finally. The mean age was 65.5 years. At the 3-month follow-up, 187(61.5%) had poor functional outcome and 70(23.0%) died. Regardless of the CS, BP CV is positively associated with poor outcome. Hypotension time was negatively associated with poor outcome. We conducted a subgroup analysis according to CS. BPV was significantly associated with mortality at 3-month and displayed a trend toward poor outcome for patients with poor CS only. The interaction between SBP CV and CS with respect to mortality after adjusting for confounding factors was statistically significant (P for interaction = 0.025) and the interaction between MAP CV and CS with respect to mortality after multivariate adjustment was also statistically significant (P for interaction = 0.005). Conclusion In MT-treated stroke patients, higher BPV in the first 72 h is significantly associated with poor functional outcome and mortality at 3-month regardless of CS. This association was also found for hypotension time. Further analysis showed CS modified the association between BPV and clinical prognosis. BPV displayed a trend toward poor outcome for patients with poor CS.

The mortality rate of acute intracerebral hemorrhage (ICH) can reach up to 40%. Although the radiomics of ICH have been linked to hematoma expansion and outcomes, no research to date has explored their correlation with mortality. In this study, we determined the admission non-contrast head CT radiomic correlates of survival in supratentorial ICH, using the Antihypertensive Treatment of Acute Cerebral Hemorrhage II (ATACH-II) trial dataset. We extracted 107 original radiomic features from n = 871 admission non-contrast head CT scans. The Cox Proportional Hazards model, Kaplan–Meier Analysis, and logistic regression were used to analyze survival. In our analysis, the “first-order energy” radiomics feature, a metric that quantifies the sum of squared voxel intensities within a region of interest in medical images, emerged as an independent predictor of higher mortality risk (Hazard Ratio of 1.64, p < 0.0001), alongside age, National Institutes of Health Stroke Scale (NIHSS), and baseline International Normalized Ratio (INR). Using a Receiver Operating Characteristic (ROC) analysis, “the first-order energy” was a predictor of mortality at 1-week, 1-month, and 3-month post-ICH (all p < 0.0001), with Area Under the Curves (AUC) of >0.67. Our findings highlight the potential role of admission CT radiomics in predicting ICH survival, specifically, a higher “first-order energy” or very bright hematomas are associated with worse survival outcomes.

Background: A major driver of individual variation in long-term outcomes following a large vessel occlusion (LVO) stroke is the degree of collateral arterial circulation. We aimed to develop and evaluate machine-learning models that quantify LVO collateral status using admission computed tomography angiography (CTA) radiomics. Methods: We extracted 1116 radiomic features from the anterior circulation territories from admission CTAs of 600 patients experiencing an acute LVO stroke. We trained and validated multiple machine-learning models for the prediction of collateral status based on consensus from two neuroradiologists as ground truth. Models were first trained to predict (1) good vs. intermediate or poor, or (2) good vs. intermediate or poor collateral status. Then, model predictions were combined to determine a three-tier collateral score (good, intermediate, or poor). We used the receiver operating characteristics area under the curve (AUC) to evaluate prediction accuracy. Results: We included 499 patients in training and 101 in an independent test cohort. The best-performing models achieved an averaged cross-validation AUC of 0.80 ± 0.05 for poor vs. intermediate/good collateral and 0.69 ± 0.05 for good vs. intermediate/poor, and AUC = 0.77 (0.67–0.87) and AUC = 0.78 (0.70–0.90) in the independent test cohort, respectively. The collateral scores predicted by the radiomics model were correlated with (rho = 0.45, p = 0.002) and were independent predictors of 3-month clinical outcome (p = 0.018) in the independent test cohort. Conclusions: Automated tools for the assessment of collateral status from admission CTA—such as the radiomics models described here—can generate clinically relevant and reproducible collateral scores to facilitate a timely treatment triage in patients experiencing an acute LVO stroke.

Purpose: Various neuroimaging methods exist to assess the collateral circulation in stroke patients but much of the evidence is based on computed tomography. Our aim was to review the evidence for using magnetic resonance imaging for collateral status evaluation pre-thrombectomy and assess the impact of these methods on functional independence. Methods: We systematically reviewed EMBASE and MEDLINE for studies that evaluated baseline collaterals using MRI pre-thrombectomy and conducted a meta-analysis to express the relationship between good collaterals (defined variably as the presence [good] vs absence [poor] or quality [ordinal scores binarized as good-moderate vs poor] of collaterals) and functional independence (modified Rankin score mRS≤2) at 90 days. Outcome data were presented as relative risk (RR, 95% confidence interval, 95%CI). We assessed for study heterogeneity, publication bias, and conducted subgroup analyses of different MRI methods and affected arterial territories. Results: From 497 studies identified, we included 24 (1957 patients) for the qualitative synthesis, and 6 (479 patients) for the metanalysis. Good pre-thrombectomy collaterals were significantly associated with favorable outcome at 90 days (RR=1.91, 95%CI=1.36–2.68], p= 0.0002) with no difference between MRI methods and affected arterial territory subgroups. There was no evidence of statistical heterogeneity (I2=25%) among studies but there was evidence of publication bias. Conclusion: In stroke patients treated with thrombectomy, good pre-treatment collaterals assessed using MRI are associated with double the rate of functional independence. However, we found evidence that relevant MR methods are heterogenous and under-reported. Greater standardization and clinical validation of MRI for collateral evaluation pre-thrombectomy are required. [ABSTRACT FROM AUTHOR]

Background: The Los Angeles Motor Scale (LAMS) is a rapid pre-hospital scale used to predict stroke severity which has also been shown to accurately predict large vessel occlusions (LVOs). However, to date there is no study exploring whether LAMS correlates with the computed tomography perfusion (CTP) parameters in LVOs. Methods: Patients with LVO between September 2019 and October 2021 were retrospectively reviewed and included if the CTP data and admission neurologic exams were available. The LAMS was documented based on emergency personnel exams or scored retrospectively using an admission neurologic exam. The CTP data was processed by RAPID (IschemaView, Menlo Park, CA, USA) with an ischemic core volume (relative cerebral blood flow [rCBF] < 30%), time-to-maximum (Tmax) volume (Tmax > 6 s delay), hypoperfusion index (HI), and cerebral blood volume (CBV) index. Spearman's correlations were performed between the LAMS and CTP parameters. Results: A total of 85 patients were included, of which there were 9 intracranial internal carotid artery (ICA), 53 proximal M1 branch middle cerebral artery M1, and 23 proximal M2 branch occlusions. Overall, 26 patients had LAMS 0–3, and 59 had LAMS 4–5. In total, LAMS positively correlated with CBF < 30% (Correlation Coefficient (CC): 0.32, p < 0.01), Tmax > 6 s (CC:0.23, p < 0.04), HI (CC:0.27, p < 0.01), and negatively correlated with the CBV index (CC:−0.24, p < 0.05). The relationships between LAMS and CBF were < 30% and the HI was more pronounced in M1 occlusions (CC:0.42, p < 0.01; 0.34, p < 0.01 respectively) and proximal M2 occlusions (CC:0.53, p < 0.01; 0.48, p < 0.03 respectively). The LAMS also correlated with a Tmax > 6 s in M1 occlusions (CC:0.42, p < 0.01), and negatively correlated with the CBV index in M2 occlusions (CC:−0.69, p < 0.01). There were no significant correlations between the LAMS and intracranial ICA occlusions. Conclusions: The results of our preliminary study indicate that the LAMS is positively correlated with the estimated ischemic core, perfusion deficit, and HI, and negatively correlated with the CBV index in patients with anterior circulation LVO, with stronger relationships in the M1 and M2 occlusions. This is the first study showing that the LAMS may be correlated with the collateral status and estimated ischemic core in patients with LVO. [ABSTRACT FROM AUTHOR]

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Background: Collateral status is an important predictor for the outcome of acute ischemic stroke with large vessel occlusion. Multiphase computed-tomography angiography (mCTA) is useful to evaluate the collateral status, but visual evaluation of this examination is time-consuming. This study aims to use an artificial intelligence (AI) technique to develop an automatic AI prediction model for the collateral status of mCTA. Methods: This retrospective study enrolled subjects with acute ischemic stroke receiving endovascular thrombectomy between January 2015 and June 2020 in a tertiary referral hospital. The demographic data and images of mCTA were collected. The collateral status of all mCTA was visually evaluated. Images at the basal ganglion and supraganglion levels of mCTA were selected to produce AI models using the convolutional neural network (CNN) technique to automatically predict the collateral status of mCTA. Results: A total of 82 subjects were enrolled. There were 57 cases randomly selected for the training group and 25 cases for the validation group. In the training group, there were 40 cases with a positive collateral result (good or intermediate) and 17 cases with a negative collateral result (poor). In the validation group, there were 21 cases with a positive collateral result and 4 cases with a negative collateral result. During training for the CNN prediction model, the accuracy of the training group could reach 0.999 ± 0.015, whereas the prediction model had a performance of 0.746 ± 0.008 accuracy on the validation group. The area under the ROC curve was 0.7. Conclusions: This study suggests that the application of the AI model derived from mCTA images to automatically evaluate the collateral status is feasible. [ABSTRACT FROM AUTHOR]

Background: Mechanical thrombectomy (MT) has been proven as an effective and safe therapy for patients with acute ischemic stroke from large vessel occlusion. However, there is still a controversial topic about post-procedural management including blood pressure (BP). Methods: A total of 294 patients who received MT in Second Affiliated Hospital of Soochow University from April 2017 to September 2021 were included consecutively. The association of blood pressure parameters (BPV and hypotension time) with poor functional outcome was evaluated using logistic regression models. Meanwhile, the effects of BP parameters on mortality was analyzed using cox proportional hazards regression models. Furthermore, the corresponding multiplicative term was added to the above models to study the interaction between BP parameters and CS. Results: Two hundred ninety four patients were included finally. The mean age was 65.5 years. At the 3-month follow-up, 187(61.5%) had poor functional outcome and 70(23.0%) died. Regardless of the CS, BP CV is positively associated with poor outcome. Hypotension time was negatively associated with poor outcome. We conducted a subgroup analysis according to CS. BPV was significantly associated with mortality at 3-month and displayed a trend toward poor outcome for patients with poor CS only. The interaction between SBP CV and CS with respect to mortality after adjusting for confounding factors was statistically significant (P for interaction = 0.025) and the interaction between MAP CV and CS with respect to mortality after multivariate adjustment was also statistically significant (P for interaction = 0.005). Conclusion: In MT-treated stroke patients, higher BPV in the first 72 h is significantly associated with poor functional outcome and mortality at 3-month regardless of CS. This association was also found for hypotension time. Further analysis showed CS modified the association between BPV and clinical prognosis. BPV displayed a trend toward poor outcome for patients with poor CS. [ABSTRACT FROM AUTHOR]

As alternative blood supply routes, collateral blood vessels can play a crucial role in determining patient outcomes in acute and chronic intracranial occlusive diseases. Studies have shown that increased collateral circulation can improve functional outcomes and reduce mortality, particularly in those who are not eligible for reperfusion therapy. This article aims to discuss the anatomy and physiology of collateral circulation, describe current imaging tools used to measure collateral circulation, and identify the factors that influence collateral status. [ABSTRACT FROM AUTHOR]

Mechanical thrombectomy (MT) is the treatment standard in eligible patients with acute ischemic stroke (AIS) secondary to large vessel occlusions (LVO). Studies have shown that good collateral status is a strong predictor of MT efficacy, thus making collateral status important to quickly assess. The Los Angeles Motor Scale is a clinically validated tool for identifying LVO in the field. The aim of this study is to investigate whether admission LAMS score is also associated with the American Society of Interventional and Therapeutic Neuroradiology (ASITN) collateral score on digital subtraction angiography (DSA).We conducted a retrospective multicenter cohort study of consecutive patients presenting with AIS caused by LVO from 9/1/2017 to 10/1/2023 with diagnostically adequate DSA imaging. Demographic, clinical, and imaging data was collected through manual chart review. Both univariate and multivariate analysis were applied to assess associations. A p-value <0.05 was considered significant.A total of 308 patients (median age: 68, IQR: 57.5–77) were included in the study. On multivariate logistic regression analysis, we found that lower admission LAMS score (adjusted OR: 0.82, 95% CI: 0.68–0.98, p < 0.05) and higher ASPECTS score (adjusted OR: 1.21, 95% CI: 1.02–1.42, p < 0.05) were independently associated with good DSA ASITN collateral score of 3-4.Admission LAMS and ASPECTS score are both independently associated with DSA ASITN collateral score. This demonstrates the capability of LAMS to act as a surrogate marker of CS in the field. [ABSTRACT FROM AUTHOR]

• The peak time delay was an independent predictor of good collaterals in AIS patients. • The peak time delay was an independent predictor of good outcomes in AIS patients. • Tissue fate were moderately positively correlated with peak density decrease. Collateral status is a pivotal determinant of clinical outcomes in acute ischemic stroke (AIS); however, its evaluation can be challenging. We investigated the predictive value of CT perfusion (CTP) derived time and density alterations versus CTP for collateral status prediction in AIS. Consecutive patients with anterior circulation occlusion within 24 h were retrospectively included. Time-density curves of the CTP specified ischemic core, penumbra, and the corresponding contralateral unaffected brain were obtained. The collateral status was dichotomised into robust (4–5 scores) and poor (0–3 scores) using multiphase collateral scoring, as described by Menon et al.. Receiver operating characteristic curves and multivariable regression analysis were performed to assess the predictive ability of CTP-designated tissue time and density alterations, CTP for robust collaterals, and favourable outcomes (mRS score of 0–2 at 90 days). One-hundred patients (median age, 68 years; interquartile range, 57–80 years; 61 men) were included. A smaller ischemic core, shorter peak time delay, lower peak density decrease, lower cerebral blood volume ratio, and cerebral blood flow ratio in the CTP specified ischemic core were significantly associated with robust collaterals (P FDR ≤ 0.004). The peak time delay demonstrated the highest diagnostic value (AUC, 0.74; P < 0.001) with 66.7 % sensitivity and 73.7 % specificity. Furthermore, the peak time delay of less than 8.5 s was an independent predictor of robust collaterals and favourable clinical outcomes. Robust collateral status was significantly associated with the peak time delay in the ischemic core. It is a promising image marker for predicting collateral status and functional outcomes in AIS. [ABSTRACT FROM AUTHOR]

Distinct subtypes of intracranial carotid artery calcification (ICAC) have been found (i.e., medial and intimal), which may differentially be associated with the formation of collaterals. We investigated the association of ICAC subtype with collateral status in patients undergoing endovascular thrombectomy (EVT) for ischemic stroke. We further investigated whether ICAC subtype modified the association between collateral status and functional outcome. We used data from 2701 patients with ischemic stroke undergoing EVT. Presence and subtype of ICAC were assessed on baseline non-contrast CT. Collateral status was assessed on baseline CT angiography using a visual scale from 0 (absent) to 3 (good). We investigated the association of ICAC subtype with collateral status using ordinal and binary logistic regression. Next, we assessed whether ICAC subtype modified the association between collateral status and functional outcome (modified Rankin Scale, 0–6). Compared to patients without ICAC, we found no association of intimal or medial ICAC with collateral status (ordinal variable). When collateral grades were dichotomized (3 versus 0–2), we found that intimal ICAC was significantly associated with good collaterals in comparison to patients without ICAC (aOR, 1.41 [95%CI:1.06–1.89]) or with medial ICAC (aOR, 1.50 [95%CI:1.14–1.97]). The association between higher collateral grade and better functional outcome was significantly modified by ICAC subtype (p for interaction = 0.01). Patients with intimal ICAC are more likely to have good collaterals and benefit more from an extensive collateral circulation in terms of functional outcome after EVT. [Display omitted] • In patients with ischemic stroke undergoing endovascular thrombectomy (EVT) , intimal carotid artery calcification (ICAC) is associated with good collaterals. • Patients with intimal ICAC benefit more from an extensive collateral circulation in terms of functional outcome after EVT. • ICAC subtype may have important clinical consequences for ischemic stroke patients. [ABSTRACT FROM AUTHOR]

Collateral status may facilitate clot removal and affect rates of successful reperfusion following endovascular therapy (EVT) for acute ischemic stroke (AIS).Following the PRISMA guidelines, a systematic literature review of the English language literature was conducted using PubMed, Scopus, Web of Science, and Embase. Papers which focused on collateral status and patients treated with EVT for AIS were included in our analysis. Outcomes of interest included collateral score grading, rates of successful reperfusion defined as thrombolysis in cerebral infarction (TICI) score 2b-3 and onset to revascularization time. We calculated pooled odds ratio (OR) or mean difference (MD) and their corresponding 95% confidence intervals (CI) based on collateral status.16 studies, with 6073 patients, were included in our analysis. Among the included studies, there were six different collateral grading scales, which were dichotomized into “good to moderate” and “poor” collaterals. Odds of successful reperfusion were significantly higher among patients with good to moderate collateral circulation compared to those with poor collaterals (OR =  1.61; 95% CI = 1.24 to 2.09; P-value < 0.001); however, there was heterogeneity among included studies (I2 = 5 4%; P-value = 0.008). Onset to revascularization time was comparable between patients with good to moderate collateral circulation compared to those with poor collaterals (MD = 3.91 min; 95% CI = −8.71 to 16.53; P-value = 0.544); however, there was heterogeneity among included studies (I2= 60%; P-value = 0.014).The presence of good collaterals may increase the odds of achieving successful reperfusion following EVT for AIS. Improved collateral flow was associated with improved angiographic outcomes, although future work is needed to determine if a causal relationship exists. [ABSTRACT FROM AUTHOR]

Introduction: We aim to investigate the correlation between presence of anterior temporal artery (ATA), the first major branch of middle cerebral artery (MCA), on conventional angiography and clinical outcome in patients with acute atherosclerotic M1-MCA occlusion. Methods: Consecutive patients with acute atherosclerotic M1-MCA occlusion from Nanjing Stroke Registry Program (NSRP) between January 2007 and December 2012 were included in this study. All patients underwent MRI followed by conventional angiography. From their data, we analyzed baseline characteristics, infarction patterns, DWI-ASPECTS, and collateral circulation. The correlation of ATA presence and good clinical outcome, modified Rankin Scale (mRS) score ≤2, at 3 months was also calculated. Results: In 98 patients meeting entry criteria, the presence of ATA was found in 44 patients. Patients with ATA present were found to have less hypertension ( p = 0.042), lower baseline National Institutes of Health Stroke Scale (NIHSS) ( p = 0.043), more small infarcts in perforating artery territory ( p = 0.013), and a higher number of DWI-ASPECTS ≥7 ( p = 0.034). Binary logistic regression analysis showed an adjusted odds ratio of 4.45 for a good outcome in patients with ATA presence (95 % CI 1.52 to 13.03, p = 0.007). Conclusion: The presence of ATA can be used as a predictor of good outcome in patients with acute atherosclerotic M1-MCA occlusion. [ABSTRACT FROM AUTHOR]