Abstract 160: Association Between Time From Stroke Onset and Flair Lesion Intensity is Modified by Status of Collateral Circulation

Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Anke Wouters ◽  
Patrick Dupont ◽  
Sören Christensen ◽  
Bo Norrving ◽  
Rico Laage ◽  
...  
Keyword(s):  
Symptom Onset ◽  
Signal Intensity ◽  
Collateral Circulation ◽  
Onset Time ◽  
Stroke Onset ◽  
Lesion Volume ◽  
Collateral Flow ◽  
Stroke Patients ◽  
Relative Signal Intensity

Introduction and hypothesis: In acute stroke patients the intensity of a FLAIR lesion in a region of diffusion restriction is associated with time from symptom onset. The DWI/FLAIR mismatch is currently used in trials for treatment of stroke patients with unknown onset time. However the accuracy of the DWI/FLAIR mismatch to predict symptom onset before 4.5h remains moderate. We hypothesized that collateral status, as assessed by the previously described hypoperfusion intensity ratio (HIR) could modify the association between time from stroke onset and FLAIR lesion intensity. Methods: From the ‘Ax200 for ischemic stroke trial’ 141 patients were included. Quantitative FLAIR maps were calculated in a voxel-based manner. For each voxel the relative signal intensity (rSI) was determined by the ratio of the signal intensity in that voxel and the median of the signal intensity in a sphere with radius 15mm positioned in the homologue voxel in the other hemisphere. Lesion volumes based on diffusion-weighted imaging and perfusion-weighted imaging were determined using RAPID software. The HIR was defined as the proportion of a Tmax >6 s lesion volume with a Tmax >10 s delay. A previously defined HIR-threshold of ≤ 0.4 dichotomized good versus poor collaterals. We studied the interaction between collateral circulation and the association between time from symptom onset and FLAIR intensity. Results: Time from symptom onset was associated with the mean FLAIR intensity in the region of non-reperfused core (b=1.05; 95%CI: 1.01-1.1). We identified an interaction between this association and collateral status (p=0.036). ROC analysis of FLAIR intensity to predict stroke onset before 4.5h showed an AUC of 0.66 (95% CI: 0. 49-0.83) for patients with good collaterals and 0.80 (95%CI: 0.71-0.90) for patients with poor collaterals. Conclusions: Our findings suggest that the progression of FLAIR intensity with time varies depending on the quality of the collateral flow. Accordingly collateral circulation influences the accuracy of FLAIR lesion intensity to predict stroke onset before 4.5h. This could be of particular importance for clinical trials enrolling patients based on the DWI/FLAIR mismatch.

Estimating nocturnal stroke onset times by magnetic resonance imaging in the WAKE-UP trial

2021 ◽  
pp. 174749302110596
Author(s):  
Bastian Cheng ◽  
Hans Pinnschmidt ◽  
Alina Königsberg ◽  
Eckhard Schlemm ◽  
Florent Boutitie ◽  
...  
Keyword(s):  
Linear Regression ◽  
Symptom Onset ◽  
Controlled Trial ◽  
Early Morning ◽  
Stroke Onset ◽  
Lesion Volume ◽  
Night Sleep ◽  
Symptom Recognition ◽  
Fluid Attenuated Inversion Recovery ◽  
Signal Intensities

Background Fluid-attenuated inversion recovery (FLAIR) sequences have gained a role to guide treatment of patients with unknown time of stroke symptom onset. Evolution of signal intensities in FLAIR is associated with time since stroke onset with continuous linear increases. Aims Estimating symptom onset during night-sleep in patients from the WAKE-UP trial based on relative signal intensities FLAIR (FLAIR-rSI) from acute stroke lesions an independent dataset (PRE-FLAIR study). Methods FLAIR-rSI was quantified in stroke lesions in PRE-FLAIR and WAKE-UP. The PRE-FLAIR study was a multicenter observational trial establishing FLAIR as a surrogate parameter for time since stroke onset. WAKE-UP was a randomized controlled trial that revealed a benefit for alteplase in patients selected based on a DWI-FLAIR mismatch. Stroke onset times were recorded in PRE-FLAIR and used to fit a linear regression model with FLAIR-rSI, adjusted for patient age and lesion volume. The model was applied to FLAIR-rSI of stroke lesions to estimate onset times in those patients enrolled in WAKE-UP who had symptom onset during night-sleep. Results FLAIR-rSI was quantified in 399 patients from PRE-FLAIR. Linear regression indicated a significant association of age ( p = 0.001), lesion volume ( p = 0.005) and FLAIR-rSI ( p < 0.001) with time since symptom onset (adjusted R2 = 0.179). In 813 patients from WAKE-UP, distribution of times of last seen well, symptom recognition and MRI examination were recorded. Median times of last seen well were 1 h before midnight (IQR 2.4 h) and symptom recognition 7 h after midnight (IRQ 2.2 h). Based on the FLAIR-rSI profiles, we estimated median stroke onset 6.1 h after midnight (IQR 2.7 h). Conclusion Nocturnal strokes during night-sleep may predominantly occur during the early morning hours. Our results are in line with evidence of characteristic diurnal patterns of cardiovascular events.

Abstract WMP120: Pre-stroke Statin Enhancement of Collateralization in Acute Ischemic Stroke

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Mengmeng Ma ◽  
Jiaying Zhu ◽  
Li He
Keyword(s):  
Ischemic Stroke ◽  
Middle Cerebral Artery ◽  
Acute Ischemic Stroke ◽  
Functional Outcome ◽  
Cerebral Artery ◽  
Collateral Circulation ◽  
Stroke Onset ◽  
Stroke Severity ◽  
Stroke Patients ◽  
Statin Use

Background: Recent studies suggested that prior statin therapy could lower the initial stroke severity and improve stroke functional outcome in case of stroke onset. It was speculated that pre-stroke statin may enhance collateral circulation and result in favorable functional outcome. This study aimed to investigate the association of pre-stroke statin use with leptomeningeal collaterals in acute ischemic stroke patients. Methods: We prospectively and consecutively enrolled 239 acute ischemic stroke patients with acute infarction due to occlusion of the middle cerebral artery within 24 hours from May 2011 to April 2017. CTA imaging was performed for all patients to detect middle cerebral artery thrombus; regional leptomeningeal collateral score (rLMCS) was used to assess the degree of collateral circulation; admission NIHSS was used to measure stroke severity; modified Rankin scale (mRS) at 90 day was used to measure outcome. Univariate and multivariate analyses were performed. Results: 239 patients met inclusion criteria. 54 patients use statin before stroke onset. Pre-stroke statin use was independently associated with good collateral circulations (rLMCS>10) (OR, 4.786; 95% CI, 1.195 - 19.171; P = 0.027). Pre-stroke statin use was not independently associated with lower stroke severity (NIHSS≤14) (OR, 1.955; 95%CI, 0.657- 5.816; P = 0.228), but pre-stroke statin use was independently associated with good outcome (mRS≤2) (OR, 3.868; 95%CI, 1.325 - 11.289; P = 0.013). Conclusion: Pre-stroke statin use seems enhance collateralization and improve clinical outcomes in patients with acute stroke. However, clinical controlled studies should be used to verify this claim.

Abstract 59: Extending the Time for Thombolysis in Emergency Neurological Deficits (EXTEND) - High Prevalence of Intracranial Vessel Occlusion in Wake-up-stroke Patients

Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Henry Ma ◽  
Bruce C Campbell ◽  
Mark W Parsons ◽  
Christopher Levi ◽  
Atte Meretoja ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Cerebral Artery ◽  
Stroke Onset ◽  
Phase Iii ◽  
Neurological Deficits ◽  
Lesion Volume ◽  
Stroke Patients ◽  
Vessel Occlusion ◽  
Intracranial Vessel ◽  
Ct Angiogram

Background: EXTEND is an investigator-initiated, randomised, double-blind and placebo-controlled Phase III trial of intravenous alteplase vs placebo in patients with ischemic stroke 4.5-9 hours from stroke onset or wake-up-stroke (WUS). The prevalence of intra-cranial vessel occlusion in WUS patients remains to be determined and can guide the development of optimal therapy for this unique group of stroke patients. Objective: To study the prevalence and characteristics of intra-cranial vessel occlusion in this WUS cohort. Methods: Ischemic stroke patients within 4.5-9 hours from stroke onset or with WUS (time of WUS onset defined as the midpoint between time to sleep and awakening with the stroke symptoms) are eligible for enrollment. Criteria for entry into the trial include perfusion-diffusion mismatch using a perfusion threshold of Tmax>6sec and a perfusion:diffusion lesion volume ratio of >1.2. Diffusion lesion volume must be <70mL based on assessment by automated RAPID software. Intra-cranial vessel occlusion was assessed on MR or CT angiogram performed at randomisation and 24 later. Two expert readers assessed these images independently. Results: 97 patients had images with adequate quality, including 63 (65%) in the WUS group with median age of 77.0 yrs (IQR 67.0, 81.0) and NIHSS of 14.0 (9.0, 19.0). 62 of 63 patients (98%) had vessel occlusion with 44.4% involving M1 of the middle cerebral artery, 17.5% M2, 4.8% M3, 25.4% both internal carotid artery (ICA) and M1, 4.8% ICA alone and 3.1% the posterior cerebral artery. The median ischemic core volume was 15.0 ml (6.5, 31.5), Tmax>6 volume 88.5ml (58.0, 122.0), mismatch volume 65.5ml (42.8, 92.0), and ratio of 4.8 (2.5, 8.7). 19 patients (30%) demonstrated recanalization on follow-up imaging. Conclusion: In WUS patients there is a very high rate of intracranial vessel occlusion with relatively large volumes of salvageable penumbral tissue. Intravenous thrombolytic therapy followed by thrombectomy in selected cases may be an appropriate therapeutic option with safety and efficacy remaining to be established in randomized controlled trials.

Comparative study of the relative signal intensity on DWI, FLAIR, and T2 images in identifying the onset time of stroke in an embolic canine model

2014 ◽  
Vol 35 (7) ◽  
pp. 1059-1065 ◽  
Author(s):  
Xiao-quan Xu ◽  
Qi-guang Cheng ◽  
Qing-quan Zu ◽  
Shan-shan Lu ◽  
Jing Yu ◽  
...  
Keyword(s):  
Comparative Study ◽  
Signal Intensity ◽  
Onset Time ◽  
Canine Model ◽  
Relative Signal Intensity

scholarly journals Risk Factors of Hypoperfusion on MRI of Ischemic Stroke Patients Within 7 Days of Onset

2021 ◽  
Vol 12 ◽  
Author(s):  
Jingjing Xiao ◽  
Huazheng Liang ◽  
Yue Wang ◽  
Shaoshi Wang ◽  
Yi Wang ◽  
...  
Keyword(s):  
Risk Factors ◽  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Onset Time ◽  
Residue Function ◽  
Stroke Onset ◽  
Stroke Patients ◽  
Metabolic Characteristics ◽  
Vascular Stenosis ◽  
Prior Stroke

Objective: Hypoperfusion is an important factor determining the prognosis of ischemic stroke patients. The present study aimed to investigate possible predictors of hypoperfusion on MRI of ischemic stroke patients within 7 days of stroke onset.Methods: Ischemic stroke patients, admitted to the comprehensive Stroke Center of Shanghai Fourth People's Hospital affiliated to Tongji University within 7 days of onset between January 2016 and June 2017, were recruited to the present study. Magnetic resonance imaging (MRI), including both diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI), was performed within 7 days of the symptom onset. Time to maximum of the residue function (Tmax) maps were automatically evaluated using the RAPID software. The volume of hypoperfusion was measured outside the infarct area based on ADC &lt; 620 × 10−6 mm2/s. The 90 d mRS score was assessed through either clinic visits or telephone calls. Multivariate step-wise analysis was used to assess the correlation between MR findings and clinical variables, including the demographic information, cardio-metabolic characteristics, and functional outcomes.Results: Among 635 patients admitted due to acute ischemic stroke within 7 days of onset, 241 met the inclusion criteria. Hypoperfusion volume of 38 ml was the best cut-off value for predicting poor prognosis of patients with cerebral infarction (90 d-mRS score ≥ 2). The incidences of MR perfusion Tmax &gt; 4–6 s maps with a volume of 0–38 mL or &gt;38 mL were 51.9% (125/241) and 48.1% (116/241), respectively. Prior stroke and vascular stenosis (≥70%) were associated with MR hypoperfusion. Multivariate step-wise analysis showed that prior stroke and vascular stenosis (≥70%) were risk factors of Tmax &gt; 4–6 s maps, and the odds ratios (OR) were 3.418 (adjusted OR 95% CI: 1.537–7.600), and 2.265 (adjusted OR, 95% CI: 1.199–4.278), respectively.Conclusion: Our results suggest that prior stroke and vascular stenosis (≥70%) are strong predictors of hypoperfusion in patients with acute ischemic stroke within 7 days of stroke onset.

Mapping a Reliable Stroke Onset Time Course Using Signal Intensity on DWI Scans

2019 ◽  
Author(s):  
Michael M. Chen ◽  
Patrick M. Chen ◽  
Lovella Hailey ◽  
Melissa Mortin ◽  
Karen Rapp ◽  
...  
Keyword(s):  
Signal Intensity ◽  
Time Course ◽  
Onset Time ◽  
Stroke Onset

Abstract 178: Infarct Growth Rate Depends on Collateral Status in Acute Ischemic Stroke Patients

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Reza Hakimelahi ◽  
Karen A Buch ◽  
Thabele M Leslie-Mazwi ◽  
Joshua A Hirsch ◽  
James D Rabinov ◽  
...  
Keyword(s):  
Growth Rate ◽  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Infarct Volume ◽  
Time Windows ◽  
Treatment Options ◽  
Contralateral Side ◽  
Stroke Onset ◽  
Lesion Volume ◽  
Stroke Patients

Introduction and Hypothesis: Multiple studies have demonstrated no statistically significant association between time after stroke onset and initial infarct volume. Factors other than time may play a role in infarct growth. We sought to investigate association between collateral status and infarct growth rate in acute ischemic stroke (AIS) patients. Methods: We included 130 consecutive patients with CTA showing ICA and/or proximal MCA occlusions who had DWI within 8 hours of stroke onset. Collateral status was categorized into three groups: poor (none or minimal), intermediate (present but < contralateral side) and good (≥ contralateral side). DWI lesion volumes were measured and infarct growth rate was calculated using MRI time after stroke onset. Mann-Whitney test and correlation coefficient were used for statistical analysis. Results: In our 130 patients, 62 female (48%), the average values (mean±SD) were: age 70 ± 17 years, NIHSS 16 ± 6, DWI volume 59 ± 65 mL, time after stroke onset 4 ± 2 hours, and infarct growth rate 17 ± 23 mL/hour. 19 (14.6%) had poor, 75 (57.7%) had intermediate, and 36 (27.7%) had good collaterals. Infarct growth rate and DWI lesion volume were significantly increased with decreased collateral quality (p<0.0004 for all group comparisons). Patients with good collaterals were younger (p=0.004 and p=0.018 compared to poor and intermediate groups respectively) and had lower NIHSS scores (p< 0.001). Time after stroke onset, gender, or occlusion site (ICA vs MCA) were not significantly different among different collateral groups. There was no correlation between time and DWI volume (r2=0.02, p=0.8) or collateral status (r2=0.05, p=0.6). There was significant correlation between collateral status and infarct growth (r2=-0.6,p<0.0001). Conclusion: AIS patients with good collaterals have small initial DWI lesion volumes and slower infarct growth rates. These patients may be candidates for treatment options outside traditional time windows.

scholarly journals Quantitative Measurements of Relative Fluid-Attenuated Inversion Recovery (FLAIR) Signal Intensities in Acute Stroke for the Prediction of Time from Symptom Onset

2012 ◽  
Vol 33 (1) ◽  
pp. 76-84 ◽  
Author(s):  
Bastian Cheng ◽  
Mathias Brinkmann ◽  
Nils D Forkert ◽  
Andras Treszl ◽  
Martin Ebinger ◽  
...  
Keyword(s):  
Acute Stroke ◽  
Symptom Onset ◽  
Visual Analysis ◽  
Onset Time ◽  
Inversion Recovery ◽  
Classification And Regression Tree ◽  
Lesion Volume ◽  
Ischemic Lesion ◽  
Quantitative Measurements ◽  
Fluid Attenuated Inversion Recovery

In acute stroke magnetic resonance imaging, a ‘mismatch’ between visibility of an ischemic lesion on diffusion-weighted imaging (DWI) and missing corresponding parenchymal hyperintensities on fluid-attenuated inversion recovery (FLAIR) data sets was shown to identify patients with time from symptom onset ≤4.5 hours with high specificity. However, moderate sensitivity and suboptimal interpreter agreement are limitations of a visual rating of FLAIR lesion visibility. We tested refined image analysis methods in patients included in the previously published PREFLAIR study using refined visual analysis and quantitative measurements of relative FLAIR signal intensity (rSI) from a three-dimensional, segmented stroke lesion volume. A total of 399 patients were included. The rSI of FLAIR lesions showed a moderate correlation with time from symptom onset ( r = 0.382, P < 0.001). A FLAIR rSI threshold of <1.0721 predicted symptom onset ≤4.5 hours with slightly increased specificity (0.85 versus 0.78) but also slightly decreased sensitivity (0.47 versus 0.58) as compared with visual analysis. Refined visual analysis differentiating between ‘subtle’ and ‘obvious’ FLAIR hyperintensities and classification and regression tree algorithms combining information from visual and quantitative analysis also did not improve diagnostic accuracy. Our results raise doubts whether the prediction of stroke onset time by visual image judgment can be improved by quantitative rSI measurements.

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