imaging-Alberta Stroke Program Early Computed Research Articles

Quantitative Assessment of Acute Intracranial Clot and Collaterals on High Resolution Magnetic Resonance Imaging.

There has been an increasing demand for imaging methods that provide a comprehensive evaluation of intracranial clot and collateral circulation, which are helpful for clinical decision-making and predicting functional outcomes. We aimed to quantitatively evaluate acute intracranial clot burden and collaterals on high-resolution magnetic resonance imaging (HR-MRI). We analyzed acute ischemic stroke patients with internal carotid artery or middle cerebral artery occlusion in a prospective multicenter study. The clot burden was scored on a scale of 0-10 based on the clot location on HR-MRI. The collateral score was assigned on a scale of 0-3 using the minimum intensity projection from HR-MRI. Uni- and multivariable logistic regression analyses were performed to assess their correlation with clinical outcome (modified Rankin Scale >2 at 90 days). Thresholds were defined to dichotomize into low and high score groups and predictive performances were assessed for clinical and radiologic outcomes. Ninety-nine patients (mean age of 60.77 ± 11.54 years) were included in the analysis. The interobserver correlation was 0.89 (95% CI: 0.77-0.95) for the clot burden score and 0.78 (95% CI: 0.53-0.90) for the collateral score. Multivariable logistic regression analysis demonstrated that the collateral score (odds ratio: 0.41, 95% CI: 0.19-0.90) was significantly associated with clinical outcomes. A better functional outcome was observed in the group with clot burden scores greater than 7 (p=0.011). A smaller final infarct size and a higher diffusion-weighted imaging-Alberta Stroke Program Early Computed Tomography Score were observed in the group with collateral scores greater than 1 (all p<0.05). HR-MRI offers a new tool for quantitative assessment of clot burden and collaterals simultaneously in future clinical practices and research endeavors.

A differential detailed diffusion-weighted imaging-ASPECTS for cerebral infarct volume measurement and outcome prediction.

Diffusion-weighted imaging-Alberta Stroke Program Early Computed Tomography Score (DWI-ASPECTS) has been used to estimate infarct core volume in acute stroke. However, the same and indiscriminate score deduction for punctate or confluent DWI high-intensity lesion might lead to variation in performance. To develop and evaluate a differential detailed DWI-ASPECTS method in comparison with the conventional DWI-ASPECTS in core infarct volume measurement and clinical outcome prediction. We retrospectively recruited patients with acute ischemic stroke (AIS) treated with endovascular treatment between April 2013 and October 2019. In differential detailed DWI-ASPECTS, restricted diffusion lesion that was punctate or less than half of a cortical region (M1-M6) would not lead to subtraction of point. A favorable outcome was modified Rankin Scale score ⩽2 at 90 days after stroke onset. Among 298 AIS patients, mean age was 75 years (interquartile range (IQR) 67-82), and 194 patients (65%) were males. Mean infarct core volume was 11 mL (IQR 3-37). Overall, the score by detailed DWI-ASPECTS was significantly higher than conventional DWI-ASPECTS (8 (7-9) vs. 7 (5-9); P < 0.01). The detailed DWI-ASPECTS resulted in a higher correlation coefficient (r) for core infarct volume estimation than the conventional DWI-ASPECTS (r = 0.832 vs. 0.773; P < 0.01). Upon re-classification of those scored ⩽6 in conventional DWI-ASPECTS (n = 134) by detailed DWI-ASPECTS, the rate of favorable outcome in patients with detailed DWI-ASPECTS >6 was significantly higher than those with ⩽6 (29 (48%) vs. 14 (19%); P < 0.01). Detailed DWI-ASPECTS appeared to provide a more accurate infarct core volume measurement and clinical outcome correlation than conventional DWI-ASPECTS among AIS patients treated with endovascular therapy.

The association between diffusion-weighted imaging-Alberta Stroke Program Early Computed Tomography Score and the outcome following mechanical thrombectomy of anterior circulation occlusion

BackgroundAlthough preoperative diffusion-weighted imaging-Alberta Stroke Program Early Computed Tomography Score (DWI-ASPECTS) is well known as a predictor of outcomes after mechanical thrombectomy (MT) for large-vessel occlusion (LVO), assessment of changes in DWI-ASPECT from before to after MT is rare. Therefore, we clarified the relationship between the change in DWI-ASPECTS and clinical outcomes. MethodsIn this retrospective single-center study, we enrolled 63 cases of anterior LVOs treated with MT between April 2015 and March 2022. Preoperative and postoperative DWI-ASPECTSs were calculated. DWI-ASPECTSs were categorized into cortical-ASPECTSs (c-ASPECTSs) and subcortical ASPECTSs and assessed. Additionally, medical variables related to patients, such as sex, age, National Institutes of Health Stroke Scale (NIHSS) score, and premorbid modified Rankin Scale (mRS) score, were evaluated. A good outcome was defined as an mRS score of 0–2 at 3 months. ResultsForty-five patients met the inclusion criteria. Nine (20 %) had a good outcome. The good outcome group showed significantly higher postoperative DWI-ASPECTs (median 8 vs. 5, p = 0.012) and c-ASPECTSs (median 4 vs. 3, p = 0.020) than the poor outcome group. No difference in DWI-ASPECTSs and c-ASPECTSs from before to after MT were significantly associated with the good outcome (p = 0.017, p = 0.016, respectively). The cut-off values for the good outcome on receiver operating characteristic curve analysis for differences between DWI-ASPECTSs and c-ASPECTSs were 0 [area under the curve (AUC) 0.77] and 0 [AUC 0.74]. Logistic regression analyses showed that baseline NIHSS score (odds ratio, 0.69; 95 % confidence interval 0.48–1.00; p = 0.046) and postoperative DWI-ASPECTS (odds ratio, 2.27; 95 % confidence interval 1.02–5.04; p = 0.039) were independent factors for the good outcome. ConclusionsThe good outcome of patients with anterior LVO was associated with no difference in DWI-ASPECTSs and c-ASPECTSs from before to after MT.

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

IntroductionThe relevance of the brush-sign remained poorly documented in large vessel occlusion (LVO). We aimed to assess the relationship between the brush-sign and collateral status and its potential impact on baseline diffusion-weighted imaging–Alberta Stroke Program Early Computed Tomography Score (DWI-ASPECTS) in acute ischemic stroke (AIS) patients eligible to mechanical thrombectomy (MT).MethodsConsecutive patients admitted in the Lyon Stroke Center with anterior circulation AIS due to intracranial internal carotid artery (ICA) and/or M1 or M2 segment of the middle cerebral artery (MCA) occlusion eligible for MT were included. The brush-sign was assessed on T2-gradient-echo MRI. Collateral status was assessed on digital subtraction angiography according to the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) score.ResultsIn this study, 504 patients were included, among which 171 (33.9%) patients had a brush-sign. Patients with a brush-sign more frequently had a poor collateral status [72 (42.1%) vs. 103 (30.9%); p = 0.017]. In univariable analysis, a DWI-ASPECTS < 7 was associated with a brush sign. Following multivariable analysis, the brush-sign no longer affected DWI-ASPECTS < 7 while the latter remained associated with younger age [odds ratio (OR) 0.97, 95% CI.96–0.99], male sex (OR 1.79, 95% CI 1.08–2.99), a higher National Institutes of Health Stroke Scale (NIHSS) score (OR 1.16, 95% CI 1.1–1.21), a poor collateral status (OR 9.35, 95% CI 5.59-16.02), MCA segment (OR 2.54, 95% CI 1.25–5.38), and intracranial ICA (OR 3.01, 95% CI 1.16–8) occlusion.Conclusions and RelevanceThe brush-sign may be a marker of poor collateral status but did not independently predict a lower DWI-ASPECTS.Clinical Trial RegistrationClinicalTrials.gov, identifier: NCT04620642.

Early successful reperfusion after endovascular therapy reduces malignant middle cerebral artery infarction occurrence in young patients with large diffusion-weighted imaging lesions.

Malignant middle cerebral artery infarction (MMI) is a severe complication of acute ischaemic stroke (AIS). The aim of our study was to assess whether successful reperfusion after endovascular therapy (EVT) in AIS with clinical and imaging predictors of MMI decreased its occurrence. Data were collected between January 2014 and July 2018 in a monocentric prospective AIS registry of patients treated with EVT. Patients selected were <65years old with severe anterior circulation AIS with a National Institutes of Health Stroke Scale score >15, baseline Diffusion-Weighted Imaging-Alberta Stroke Program Early Computed Tomography Score≤6 and baseline diffusion-weighted imaging lesion volume >82mL within 6h of symptom onset. Successful reperfusion was defined as a Thrombolysis in Cerebral Ischemia score≥2b. Occurrence of MMI was the primary endpoint. A total of 66 EVT-treated patients were included in our study. MMI occurred in 27 patients (41%). In unadjusted analysis, successful reperfusion was associated with fewer MMIs (31.8% vs. 65.0%; P=0.015) and with more favorable outcome at 3months (50% vs. 20%; P=0.023). In multivariate analysis, successful reperfusion was associated with an adjusted odds ratio (95% confidence intervals) of 0.35 (0.10-1.12) for MMI and 2.77 (0.84-10.43) for 3-month favorable outcome occurrence. Early successful reperfusion performed in patients with AIS with clinical and imaging predictors of MMI was associated with decreased MMI occurrence. Reperfusion status might be considered in evaluating the need for craniectomy in patients with early predictors of MMI.

Results of Therapy Using Oral Anticoagulants in the Acute Phase after Mechanical Thrombectomy.

The usage of oral anticoagulants (OACs) in the acute phase of cerebral infarction has increased, but the optimal timing for starting OACs after mechanical thrombectomy (MT) is unclear. We report the usage of OACs after MT at our hospital and evaluated the outcomes. OACs were selected as secondary preventive drugs for 64 patients who underwent MT for anterior circulatory embolism between July 2016 and January 2019. Of the 64 patients, 28 and 36 received direct oral anticoagulants (DOACs) and warfarin (Wf), respectively. We compared the frequency of intracranial hemorrhage in the acute phase and that of recurrent cerebral infarction within 30 days. The median diffusion-weighted imaging-Alberta Stroke Program Early Computed Tomography Scores + white matter (DWI-ASPECTS + W) score at admission was 7.5 (IQR 6-9)/8 (IQR, 6-9) in the DOACs group/Wf group. The rate of recanalization with modified thrombolysis in cerebral infarction (TICI) ≥2B by MT was 89.3/80.6%. In patients with subarachnoid hemorrhage (SAH) associated with MT and patients with hemorrhagic transformation (HT) on MRI the next day, administration was started after hemostasis. The median timing of the first anticoagulant administration was 3 (IQR, 2-4)/2 (IQR, 1-4) days. In the case of no HT the next day, the rate of new HT after 1 week was 7.1%/29.1%. In the case of HT the next day, the rate of HT deterioration the next day was 7.1%/16.6%. The percentage of symptomatic bleeding was 0%/2.8%. The percentage of recurrent cerebral infarction within 30 days was 0%/2.8%. OACs in the acute phase after MT can be safely used and are expected to be effective at preventing recurrence.

Vascular Hyperintensity on Fluid-Attenuated Inversion Recovery Indicates the Severity of Hypoperfusion in Acute Stroke

Background and AimAlthough fluid-attenuated inversion recovery vascular hyperintensities may be frequently seen in acute large-artery ischemic stroke, reports on their prognostic utility had been conflicting due to lack of quantitative evaluation of the perfusion status based on the signal intensity. We hypothesized that greater hyperintensity represents more severe hypoperfusion. MethodsOverall, 27 patients with acute occlusion of the proximal middle cerebral artery were divided into 2 groups, based on their signal intensity in the insular segment of middle cerebral artery on the affected side, relative to that of the insular cortex: the low signal intensity group (hypo- or isointense signals, n = 12) and the high signal intensity group (hyperintense signals, n = 15). Using dynamic susceptibility contrast magnetic resonance imaging, we assessed the time of the maximum value of the residue function and mean transit time, in the entire middle cerebral artery cortical area and diffusion-weighted imaging-Alberta Stroke Program Early Computed Tomography Score regions, including the corona radiata. ResultsThe high signal intensity group had significantly longer time of the maximum value of the residue function in all the diffusion-weighted imaging-Alberta Stroke Program Early Computed Tomography Score regions, except the M3 and M6 regions, and significantly longer mean transit time in the M1 and M4 regions. ConclusionsQuantitative analysis of the perfusion parameters revealed more severely compromised and widely disturbed perfusion status in the high signal intensity group than in the low signal intensity group.

Modified diffusion-weighted imaging-Alberta Stroke Program Early Computed Tomography Score including deep white matter lesions predicts symptomatic intracerebral hemorrhage following intravenous thrombolysis

The Alberta Stroke Program Early Computed Tomography Score (ASPECTS) is widely used for the assessment of early ischemic changes (EICs) before thrombolysis. However, for symptomatic intracerebral hemorrhage (sICH) following intravenous recombinant tissue plasminogen activator (rt-PA), the prediction abilities of CT-ASPECTS, diffusion-weighted imaging (DWI)-ASPECTS, and DWI-ASPECTS including EICs in deep white matter (DWI-ASPECTS + W) are unclear. We investigated associations between each score and sICH following intravenous rt-PA. Data from consecutive patients who received intravenous rt-PA for acute ischemic stroke from 2005 to 2015 in four hospitals were retrospectively screened. We included data from patients who had undergone both CT and magnetic resonance imaging before thrombolysis and without evidence of posterior circulation stroke. We analyzed the ability of CT-ASPECTS, DWI-ASPECTS, and DWI-ASPECTS + W to predict sICH, accompanied by an increase in the National Institutes of Health Stroke Scale (NIHSS) score of ≥ 4 within the initial 36 h. Of 455 patients (273 men, median 75 years old), sICH occurred in 15 patients (3.3%). Receiver operating characteristics curve analysis showed that the optimal cut-offs of CT-ASPECTS, DWI-ASPECTS, and DWI-ASPECTS + W for predicting sICH were ≤ 9 (sensitivity 60.0%, specificity 59.8%, c-statistic 0.625), ≤ 6 (sensitivity 53.3%, specificity 80.9%, c-statistic 0.718), and ≤ 8 (sensitivity 86.7%, specificity 55.9%, c-statistic 0.756), respectively. A DWI-ASPECTS + W of ≤ 8 was independently associated with sICH (odds ratio 5.21, 95% confidence interval 1.30–35.31) after adjustment for pretreatment with antithrombotic agents, pretreatment NIHSS score, and large artery occlusions. DWI-ASPECTS + W predicted sICH in patients with acute anterior circulation stroke receiving intravenous rt-PA.

Acute ischemic stroke patients with diffusion-weighted imaging-Alberta Stroke Program Early Computed Tomography Score \u2264\u20095 can benefit from endovascular treatment: a single-center experience and literature review

PurposeThe recommendation strength of the guidelines for mechanical thrombectomy among patients with large pre-treatment core infarct is weak. We evaluated the safety and outcome of endovascular treatment for acute ischemic stroke with diffusion-weighted imaging-Alberta Stroke Program Early Computed Tomography Score (DWI-ASPECTS) ≤ 5.MethodsData on acute ischemic stroke patients with DWI-ASPECTS ≤ 5 who underwent endovascular treatment within 6 h, or presented an arterial spin labeling-DWI (ASL-DWI) mismatch within 12 h, at our center were retrospectively collected. We report the clinical characteristics and outcome of every patient, and review the relevant literature.ResultsAmong the 19 patients who were enrolled, all experienced successful reperfusion, and 10 achieved a favorable outcome (modified Rankin scale (mRS) ≤ 2). Two patients presented with symptomatic intracranial hemorrhage (sICH); both of them had a poor outcome (mRS > 2).ConclusionAcute ischemic stroke patients with large DWI lesions caused by large vessel occlusion can achieve a favorable clinical outcome with endovascular treatment if recanalization is performed within 6 h, or after 6 h in case of an ASL-DWI mismatch.

Correction to: Successful Reperfusion With Mechanical Thrombectomy Is Associated With Reduced Disability and Mortality in Patients With Pretreatment Diffusion-Weighted Imaging-Alberta Stroke Program Early Computed Tomography Score ≤6.

In the article by Desilles et al, “Successful Reperfusion With Mechanical Thrombectomy Is Associated With Reduced Disability and Mortality in …

Correction to: Successful Reperfusion With Mechanical Thrombectomy Is Associated With Reduced Disability and Mortality in Patients With Pretreatment Diffusion-Weighted Imaging-Alberta Stroke Program Early Computed Tomography Score ≤6.

Correction to: Successful Reperfusion With Mechanical Thrombectomy Is Associated With Reduced Disability and Mortality in Patients With Pretreatment Diffusion-Weighted Imaging-Alberta Stroke Program Early Computed Tomography Score ≤6.

Successful Reperfusion With Mechanical Thrombectomy Is Associated With Reduced Disability and Mortality in Patients With Pretreatment Diffusion-Weighted Imaging-Alberta Stroke Program Early Computed Tomography Score ≤6.

In acute ischemic stroke patients, diffusion-weighted imaging (DWI)-Alberta Stroke Program Early Computed Tomography Score (ASPECTS) is correlated with infarct volume and is an independent factor of functional outcome. Patients with pretreatment DWI-ASPECTS ≤6 were excluded or under-represented in the recent randomized mechanical thrombectomy trials. Our aim was to assess the impact of reperfusion in pretreatment DWI-ASPECTS ≤6 patients treated with mechanical thrombectomy. We analyzed data collected between January 2012 and August 2015 in a bicentric prospective clinical registry of consecutive acute ischemic stroke patients treated with mechanical thrombectomy. Every patient with a documented internal carotid artery or middle cerebral artery occlusion with pretreatment DWI-ASPECTS ≤6 was eligible for this study. The primary end point was a favorable outcome defined by a modified Rankin Scale score ≤2 at 90 days. Two hundred and eighteen patients with a DWI-ASPECTS ≤6 were included. Among them, 145 (66%) patients had successful reperfusion at the end of mechanical thrombectomy. Reperfused patients had an increased rate of favorable outcome (38.7% versus 17.4%; P=0.002) and a decreased rate of mortality at 3 months (22.5% versus 39.1%; P=0.013) compared with nonreperfused patients. The symptomatic intracranial hemorrhage rate was not different between the 2 groups (13.0% versus 14.1%; P=0.83). However, in patients with DWI-ASPECTS <5, favorable outcome was low (13.0% versus 9.5%; P=0.68) with a high mortality rate (45.7% versus 57.1%; P=0.38) with or without successful reperfusion. Successful reperfusion is associated with reduced mortality and disability in patients with a pretreatment DWI-ASPECTS ≤6. Further data from randomized studies are needed, particularly in patients with DWI-ASPECTS <5.

Endovascular Management of Acute Ischemic Strokes with Tandem Occlusions

Background: Ischemic strokes with tandem occlusions are associated with a poor prognosis. Recent studies demonstrating the effectiveness of endovascular treatment for large vessel occlusions have shown less impressive results in patients with tandem occlusions than in those with isolated intracranial occlusions. Also, the indications and effects of carotid stenting remain unclear. Methods: From a prospectively gathered registry, we analyzed data of 70 consecutive patients who underwent mechanical endovascular treatment for acute stroke with tandem occlusions from November 2011 to August 2014. Clinical (including demographics, National Institutes of Health Stroke Scale (NIHSS), and stroke etiology), imaging (including diffusion-weighted imaging-Alberta Stroke Program Early Computed Tomography Score), and endovascular treatment data were assessed and reviewed in consensus by 2 observers. Good clinical outcome was defined as a modified Rankin Scale of ≤2 at 3-month follow-up. Results: At 3-month follow-up, 50.8% had a poor clinical outcome, including death in 13.4%. Lower NIHSS (initial, at day 1, and at discharge) and successful recanalization (thrombolysis in cerebral infarction 2b-3) were associated with a good clinical outcome (p < 0.05). There were no statistically significant differences between patients with a good or poor clinical outcome in terms of intravenous (IV) tissue plasminogen activator use, delay between symptom onset and recanalization, and endovascular technique including the carotid stenting. Conclusions: Despite the recent randomized control trials demonstrating the effectiveness of thrombectomy, there is still a research gap about tandem occlusions. This subtype of stroke, which usually responds poorly to IV thrombolysis, is also difficult to treat by endovascular means. Guidelines for the endovascular management of tandem occlusions are needed.

Validity of acute stroke lesion volume estimation by diffusion-weighted imaging-Alberta Stroke Program Early Computed Tomographic Score depends on lesion location in 496 patients with middle cerebral artery stroke.

Alberta Stroke Program Early Computed Tomographic Score (ASPECTS) has been used to estimate diffusion-weighted imaging (DWI) lesion volume in acute stroke. We aimed to assess correlations of DWI-ASPECTS with lesion volume in different middle cerebral artery (MCA) subregions and reproduce existing ASPECTS thresholds of a malignant profile defined by lesion volume ≥100 mL. We analyzed data of patients with MCA stroke from a prospective observational study of DWI and fluid-attenuated inversion recovery in acute stroke. DWI-ASPECTS and lesion volume were calculated. The population was divided into subgroups based on lesion localization (superficial MCA territory, deep MCA territory, or both). Correlation of ASPECTS and infarct volume was calculated, and receiver-operating characteristics curve analysis was performed to identify the optimal ASPECTS threshold for ≥100-mL lesion volume. A total of 496 patients were included. There was a significant negative correlation between ASPECTS and DWI lesion volume (r=-0.78; P<0.0001). With regards to lesion localization, correlation was weaker in deep MCA region (r=-0.19; P=0.038) when compared with superficial (r=-0.72; P<0.001) or combined superficial and deep MCA lesions (r=-0.72; P<0.001). Receiver-operating characteristics analysis revealed ASPECTS≤6 as best cutoff to identify ≥100-mL DWI lesion volume; however, positive predictive value was low (0.35). ASPECTS has limitations when lesion location is not considered. Identification of patients with malignant profile by DWI-ASPECTS may be unreliable. ASPECTS may be a useful tool for the evaluation of noncontrast computed tomography. However, if MRI is used, ASPECTS seems dispensable because lesion volume can easily be quantified on DWI maps.