Magnetic resonance imaging-based changes in vascular morphology and cerebral perfusion in subacute ischemic stroke

MRI-based vessel size imaging (VSI) allows for in-vivo assessment of cerebral microvasculature and perfusion. This exploratory analysis of vessel size (VS) and density (Q; both assessed via VSI) in the subacute phase of ischemic stroke involved sixty-two patients from the BAPTISe cohort (‘Biomarkers And Perfusion--Training-Induced changes after Stroke’) nested within a randomized controlled trial (intervention: 4-week training vs. relaxation). Relative VS, Q, cerebral blood volume (rCBV) and –flow (rCBF) were calculated for: ischemic lesion, perilesional tissue, and region corresponding to ischemic lesion on the contralateral side (mirrored lesion). Linear mixed-models detected significantly increased rVS and decreased rQ within the ischemic lesion compared to the mirrored lesion (coefficient[standard error]: 0.2[0.08] p = 0.03 and −1.0[0.3] p = 0.02, respectively); lesion rCBF and rCBV were also significantly reduced. Mixed-models did not identify time-to-MRI, nor training as modifying factors in terms of rVS or rQ up to two months post-stroke. Larger lesion VS was associated with larger lesion volumes (β 34, 95%CI 6.2–62; p = 0.02) and higher baseline NIHSS (β 3.0, 95%CI 0.49–5.3;p = 0.02), but was not predictive of six-month outcome. In summary, VSI can assess the cerebral microvasculature and tissue perfusion in the subacute phases of ischemic stroke, and may carry relevant prognostic value in terms of lesion volume and stroke severity.

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

Neuroradiology ◽

10.1007/s00234-021-02762-3 ◽

2021 ◽

Author(s):

Kilian Fröhlich ◽

Gabriela Siedler ◽

Svenja Stoll ◽

Kosmas Macha ◽

Thomas M. Kinfe ◽

...

Keyword(s):

Ischemic Stroke ◽

Middle Cerebral Artery ◽

Acute Ischemic Stroke ◽

Cerebral Artery ◽

Posterior Circulation ◽

Neurological Deficits ◽

Stroke Severity ◽

Lesion Volume ◽

Middle Cerebral Artery Territory ◽

Cerebral Lesion

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

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Associations of Ischemic Lesion Volume With Functional Outcome in Patients With Acute Ischemic Stroke

Stroke ◽

10.1161/strokeaha.116.015156 ◽

2017 ◽

Vol 48 (5) ◽

pp. 1233-1240 ◽

Cited By ~ 20

Author(s):

Amber Bucker ◽

Anna M. Boers ◽

Joseph C.J. Bot ◽

Olvert A. Berkhemer ◽

Hester F. Lingsma ◽

...

Keyword(s):

Ischemic Stroke ◽

Acute Ischemic Stroke ◽

Functional Outcome ◽

Lesion Volume ◽

Ischemic Lesion

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Clinical and Radiological Correlates of Reduced CBF Measured Using MRI

Stroke ◽

10.1161/str.32.suppl_1.317-a ◽

2001 ◽

Vol 32 (suppl_1) ◽

pp. 317-318

Author(s):

Vincent N Thijs ◽

Tobias Neumann-Haefelin ◽

Michael E Moseley ◽

Michael P Marks ◽

Gregory W Albers

Keyword(s):

Symptom Onset ◽

Cerebral Blood Volume ◽

Arterial Input Function ◽

Mean Transit Time ◽

Input Function ◽

Lesion Volume ◽

Time Curve ◽

Measured Concentration ◽

Ischemic Lesion ◽

Adc Values

11 Background and purpose Methods for determining CBF using IV bolus tracking MRI have recently become available. Reduced apparent diffusion coefficient (ADC) values of brain tissue are associated with reductions in regional cerebral blood flow (rCBF). We studied the clinical and radiological features of patients with severe reductions of rCBF on MRI and analysed the relationship between reduced rCBF and ADC. Methods We studied patients with non-lacunar acute ischemic stroke in whom PWI and DWI MRI were performed within 7 hours after symptom onset. A PWI>DWI mismatch of >20% was required. Maps of rCBF, cerebral blood volume (rCBV) and mean transit time (rMTT) were generated after deconvoluting the measured concentration-time curve with the arterial input function using singular value decomposition. The ischemic lesion was outlined on the MTT map and the region of interest (ROI) transferred to the rCBF and rCBV map. ADC-maps were calculated. ADC lesions were defined as regions with ADC values ≤ 550 μm m2/sec. We compared the characteristics of patients with ischemic lesions that had a relative CBF of <50% to the contralateral hemisphere to patients with lesions that had relative CBF of >50%. Characteristics analysed included age, time to MRI, baseline NIHSS, mean ADC, DWI lesion volume, PWI lesion volume and absolute mismatch volume. Results Fifteen patients with an initial PWI>DWI mismatch of >20% were included. Ten had lesions with rCBF of >50% (median 60%) and five patients had rCBF of <50% (median 27.7%). Patients with rCBF <50% had lower ADC values (median 431 μmm2/sec versus 506 μ mm2/sec, p=0.028), larger DWI volumes (median 75.6 cm 3 versus 8.6 cm 3 , p=0.001) and larger PWI lesions as defined by the MTT volume (median 193 cm 3 versus 69 cm 3 , p=0.028) and more severe baseline NIHSS scores (median 18 versus 9, p=0.019). The rMTT and rCBV of the lesions were similar in both groups, as were the age, the absolute mismatch volume and the time from symptom onset to MRI. Conclusion These data indicate that ischemic lesions with severe CBF reductions, measured with new MRI techniques, are associated with a lower mean ADC, larger DWI and PWI lesion volumes and a higher NIHSS score.

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

Stroke ◽

10.1161/str.52.suppl_1.p348 ◽

2021 ◽

Vol 52 (Suppl_1) ◽

Author(s):

Brian Tsui ◽

Iris Chen ◽

Joe Qiao ◽

Kasra Khatibi ◽

Lucido Ponce Mejia ◽

...

Keyword(s):

Ischemic Stroke ◽

Acute Ischemic Stroke ◽

Perfusion Imaging ◽

Intensity Ratio ◽

Roc Analysis ◽

Cerebral Blood Volume ◽

Imaging Biomarker ◽

Lesion Volume ◽

Significant Difference ◽

Sensitivity Specificity

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

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Structural integrity of white matter tracts as a predictor of acute ischemic stroke outcome

International Journal of Stroke ◽

10.1177/1747493020915251 ◽

2020 ◽

Vol 15 (9) ◽

pp. 965-972

Author(s):

Deepthi Rajashekar ◽

Pauline Mouchès ◽

Jens Fiehler ◽

Bijoy K Menon ◽

Mayank Goyal ◽

...

Keyword(s):

Ischemic Stroke ◽

White Matter ◽

Acute Ischemic Stroke ◽

Support Vector Regression ◽

Support Vector ◽

Stroke Severity ◽

Lesion Volume ◽

White Matter Tract ◽

Support Vector Regression Model ◽

White Matter Tracts

Background and purpose Clinical assessment scores in acute ischemic stroke are only moderately correlated with lesion volume since lesion location is an important confounding factor. Many studies have investigated gray matter indicators of stroke severity, but the understanding of white matter tract involvement is limited in the early phase after stroke. This study aimed to measure and model the involvement of white matter tracts with respect to 24-h post-stroke National Institutes of Health Stroke Scale (NIHSS). Material and methods A total of 96 patients (50 females, mean age 66.4 ± 14.0 years, median NIHSS 5, interquartile range: 2–9.5) with follow-up fluid-attenuated inversion recovery magnetic resonance imaging data sets acquired one to seven days after acute ischemic stroke onset due to proximal anterior circulation occlusion were included. Lesions were semi-automatically segmented and non-linearly registered to a common reference atlas. The lesion overlap and tract integrity were determined for each white matter tract in the AALCAT atlas and used to model NIHSS outcomes using a supervised linear-kernel support vector regression method, which was evaluated using leave-one-patient-out cross validation. Results The support vector regression model using the tract integrity and tract lesion overlap measurements predicted the 24-h NIHSS score with a high correlation value of r = 0.7. Using the tract overlap and tract integrity feature improved the modeling accuracy of NIHSS significantly by 6% (p < 0.05) compared to using overlap measures only. Conclusion White matter tract integrity and lesion load are important predictors for clinical outcome after an acute ischemic stroke as measured by the NIHSS and should be integrated for predictive modeling.

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High Speed Diffusion Magnetic Resonance Imaging of Ischemia and Spontaneous Periinfarct Spreading Depression after Thromboembolic Stroke in the Rat

Journal of Cerebral Blood Flow & Metabolism ◽

10.1097/00004647-200012000-00003 ◽

2000 ◽

Vol 20 (12) ◽

pp. 1636-1647 ◽

Cited By ~ 15

Author(s):

Andreas Kastrup ◽

Tobias Neumann-Haefelin ◽

Michael E. Moseley ◽

Alex de Crespigny

Keyword(s):

Temporal Resolution ◽

High Speed ◽

Spreading Depression ◽

Tissue Injury ◽

Lesion Volume ◽

Thromboembolic Stroke ◽

Ischemic Lesion ◽

Intracellular Space ◽

Ischemic Core

Spontaneous episodes of transient cell membrane depolarization (spreading depression [SD]) occur in the surroundings of experimental stroke lesions and are believed to contribute to infarct growth. Diffusion-weighted imaging (DWI) is capable of detecting the water shifts from extracellular to intracellular space associated with SD waves and ischemia, and can make in vivo measurements of these two features on a pixel-by-pixel basis with good temporal resolution. Using continuous high speed DWI with a temporal resolution of 12 seconds over a period of 3 hours, the in vivo contribution of spontaneous SDs to the development of ischemic tissue injury was examined in 8 rats using a thromboembolic stroke model. During the observation period, the initial lesion volume increased in 4 animals, remained unchanged in 1 animal, and decreased in 3 animals (most likely because of spontaneous clot lysis). Irrespective of the lesion evolution patterns, animals demonstrated 6.5 ± 2.1 spontaneous SDs outside of the ischemic core. A time-to-peak analysis of apparent diffusion coefficient (ADC) changes for each SD wave demonstrated multidirectional propagation patterns from variable initiation sites. Maps of the time constants of ADC recovery, reflecting the local energy supply and cerebral blood flow, revealed prolonged recovery times in areas close to the ischemic core. However, repetitive SD episodes in the periinfarct tissue did not eventually lead to permanent ADC reductions. These results suggest that spontaneous SD waves do not necessarily contribute to the expansion of the ischemic lesion volume in this model.

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Impact of Collateral Status on Neuroprotective Effect of Cyclosporine A in Acute Ischemic Stroke

Current Neurovascular Research ◽

10.2174/1567202616666190618094014 ◽

2019 ◽

Vol 16 (2) ◽

pp. 173-177

Author(s):

Norbert Nighoghossian ◽

Lucie Cornut ◽

Camille Amaz ◽

Omer Eker ◽

Nathan Mewton ◽

...

Keyword(s):

Ischemic Stroke ◽

Acute Ischemic Stroke ◽

Cyclosporine A ◽

Neuroprotective Effect ◽

Additional Benefit ◽

Lesion Volume ◽

Dynamic Susceptibility ◽

Collateral Flow ◽

Dynamic Susceptibility Contrast ◽

Ischemic Lesion

Background: Neuroprotection for acute ischemic stroke remains an elusive goal. Intracranial collaterals may favor neuroprotective drugs delivery at the acute stage of ischemic stroke. A recent phase 2 study showed that cyclosporine A (CsA) reduced ischemic damage in patients with a proximal occlusion who experienced effective recanalization. Collateral flow may improve this benefit. Materials & Methods: Collateral supply was assessed using dynamic susceptibility contrast MRI in 47 patients among the 110 patients from the original study and were graded in two groups: good collaterals and poor collaterals. Patients with good collaterals had significantly smaller initial infarct in both CsA group (p = 0.003) and controls (p = 0.016). Similarly, the final lesion volume was significantly lower in patients with good collaterals in both groups. Results: In patients with either good or poor collaterals CsA showed no additional benefit on ischemic lesion progression and final infarct size at day 30. Conclusion: We failed to demonstrate any significant additional benefit of CsA in patients with good collateral circulation.

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Abstract 100: Right Insular Infarction is an Independent Predictor of Mortality in Ischemic Stroke

Stroke ◽

10.1161/str.46.suppl_1.100 ◽

2015 ◽

Vol 46 (suppl_1) ◽

Author(s):

Laura Hanne ◽

Peter Brunecker ◽

Matthias Endres ◽

Jochen B Fiebach ◽

Martin Ebinger

Keyword(s):

Ischemic Stroke ◽

Multivariate Regression ◽

Independent Predictor ◽

Lesion Volume ◽

Regression Analyses ◽

Imaging Studies ◽

Ischemic Lesion ◽

Patients At Risk ◽

The Right

Introduction: The association between insular infarction and mortality has often been described. However, whether this is simply due to higher lesion volumes is still controversial. Hypothesis: We hypothesized that there is an association between insular infarction and mortality independent of lesion volume. Methods: We included consecutive stroke patients between 01.09.2008 and 11.11.2012 from the 1000Plus data base with an acute ischemic lesion on diffusion-weighted imaging on day one and a completed 90 days follow-up. Insular location of the infarction was determined using the Stroke Lesion Atlas (SLA). The SLA is an in-house developed spatial database for analyses of imaging studies (Figure). In multivariate regression analyses of mortality and insular infarcts we adjusted for age, lesion volume, atrial fibrillation, NIHSS, capsular infarcts, and left hemispheric infarcts. Results: We included 718 patients. Out of 165 patients with insular infarcts 20 patients died; among the 553 patients with lesions outside the Insula 16 patients died (mortality 12% vs. 3%; p<.001). In analyses adjusting for all mentioned confounders insular infarction was not an independent predictor of mortality. After exclusion of NIHSS insular infarcts were independently associated with mortality (OR=3.003, CI 1.41 - 6.38, p=.004). Right insular infarction was an independent mortality predictor adjusted for all confounders including the NIHSS (OR=2.793, CI 1.27 - 6.15, p=.011). Conclusion: Right insular involvement is an independent predictor of mortality in ischemic stroke and may be used to improve identification of patients at risk. Figure. Lesion overlap of patients who survived (A) or died (B). Red indicates voxels involved in at least 15% of patients. Deceased patients show a maximum lesion overlap in the right Insula.

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Abstract P317: White Matter Hyperintensity Lesion Burden Modulates Functional Outcome After Acute Ischemic Stroke

Stroke ◽

10.1161/str.52.suppl_1.p317 ◽

2021 ◽

Vol 52 (Suppl_1) ◽

Author(s):

Anna K Bonkhoff ◽

Sungmin Hong ◽

Markus Schirmer ◽

Martin Bretzner ◽

Anne-Katrin Giese ◽

...

Keyword(s):

Ischemic Stroke ◽

White Matter ◽

Acute Ischemic Stroke ◽

Functional Outcome ◽

White Matter Hyperintensity ◽

Study Cohort ◽

Stroke Severity ◽

Ischemic Lesion ◽

Long Term Outcome ◽

Index Stroke

Introduction: As a radiographic signature of end-stage small vessel disease, white matter hyperintensity (WMH) burden impacts recovery and outcomes after acute ischemic stroke (AIS). In this study, we sought to investigate the effect of WMH volume (WMHv) on stroke severity and functional outcomes independent of the infarct size and topography. Methods: We analyzed 503 AIS patients with MRI data obtained on admission for index stroke enrolled in the multi-center MRI-GENIE study (cohort 1), followed by validation of the findings in an independent single-site study of 555 AIS patients (cohort 2). Stroke severity (NIHSS score) at index stroke and the long-term outcome (3-6 months mRS score) were modeled via Bayesian linear regression. Models included WMHv, age, sex, a 10-dimensional spatial ischemic lesion representation, acute infarct (DWI) volume, and common vascular risk factors (hypertension, diabetes mellitus, atrial fibrillation, coronary artery disease). Results: Cohorts did not differ significantly in major clinical characteristics [cohort 1: age: 65.0±14.6, 41% female, NIHSS: 5.5±5.4, mRS: 1(iqr 2); cohort 2: age: 65.0±14.8, 38% female, NIHSS: 5.0±6.0, mRS: 1(iqr 3), p >0.05 for all comparisons]. WMHv did not substantially affect AIS severity ( Fig A ); in contrast, it emerged as an independent predictor of functional outcome in both datasets ( Fig B ). Conclusions: When accounted for AIS lesion topography and stroke volume, total WMH lesion burden did not appear to modulate initial stroke severity but was associated with worse functional post-stroke outcomes. Future studies are needed to explore potential origins of these detrimental effects of pre-existing WMH burden on recovery after AIS.

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Abstract 1911: Recanalization of Proximal Arterial Occlusion in the SENTIS Trial

Stroke ◽

10.1161/str.43.suppl_1.a1911 ◽

2012 ◽

Vol 43 (suppl_1) ◽

Author(s):

David S Liebeskind ◽

Ashfaq Shuaib ◽

Martin Köhrmann ◽

William P Dillon ◽

Songling Liu ◽

...

Keyword(s):

Logistic Regression ◽

Ischemic Stroke ◽

Acute Ischemic Stroke ◽

Medical History ◽

Controlled Trial ◽

Arterial Occlusion ◽

Stroke Severity ◽

Nihss Score ◽

Logistic Regression Models ◽

Multivariable Logistic Regression

Background: Collateral circulation may enhance recanalization in acute ischemic stroke. Augmentation of collaterals with partial aortic occlusion may promote recanalization and thereby influence outcomes in the SENTIS randomized controlled trial of the NeuroFlo device. We conducted a post hoc analysis of angiography acquired in SENTIS to evaluate potential differences in recanalization rates between NeuroFlo-treated and non-treated arms, accounting for site of arterial occlusion. Methods: Blinded imaging expert review of baseline and 6-hour follow-up angiography (CTA, MRA, or DSA) from the core lab was conducted for evaluation of recanalization. Recanalization was defined as TIMI 2-3 in the arterial segment distal to baseline occlusion. Baseline demographics, stroke presentation characteristics, and medical history variables were analyzed with respect to recanalization in univariate and subsequent multivariable logistic regression models after adjusting by treatment arm. Results: Serial angiography was available in 109/515 SENTIS subjects, including 56 in the treatment arm and 53 in the non-treated arm. Baseline demographics, stroke presentation characteristics, and medical history variables did not differ statistically between arms. Across all sites of arterial occlusion, recanalization occurred in 25.7% of cases, with similar rates between device (25.0%) and medical therapy (26.4%) arms. Age and baseline stroke severity (NIHSS score) were significant predictors of recanalization in univariate analyses. Multivariable logistic regression analyses confirmed that baseline NIHSS score was the sole predictor of recanalization (OR 0.90, p=0.0458) per one unit increase, with decreased recanalization in more severe strokes. Device treatment was not associated with significant increases in recanalization rates (p=NS). Recanalization of terminal internal carotid artery (12.5%), proximal MCA or M1 (17.9%) and M2 (46.7%) occlusions was not different between arms (all p=NS). Recanalization of proximal arterial occlusion in acute ischemic stroke cases enrolled in SENTIS was more frequent in M2 occlusions. Conclusions: More severe strokes at baseline were less likely to recanalize and device therapy did not increase recanalization rates. Treatment with the NeuroFlo device may invoke mechanisms of collateral perfusion distinct from direct arterial recanalization.

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