Abstract W P32: Association of Low Cerebral Blood Volume With Negative FLAIR Hyperintensity in Acute Ischemic Stroke

Objective: FLAIR hyperintensity is being used in clinical trials as a surrogate imaging biomarker for stroke onset time to test the safety of thrombolysis. Studies have shown that patients with negative and positive FLAIR hyperintensity overlap at similar time points from stroke onset in the early phase of acute ischemic stroke (AIS). Hyperintensity on FLAIR MRI likely represents increased tissue water content. We sought to determine if cerebral blood volume (CBV) mediates FLAIR hyperintensity in the early phase of AIS. Methods: AIS patients seen in 2012 were included in the study if i) onset time was known, ii) an MRI with perfusion was performed within 12 hours of onset time, iii) had imaging confirmed vascular occlusion of ICA, M1, or M2. Following co-registration of raw perfusion images with FLAIR, CBV maps were generated using PMA ASIST™ software. Two raters blinded to clinical information separately evaluated the DWI, FLAIR and CBV maps and measured the signal intensity ratio (SIR) for the brightest region on FLAIR normalized by homologous contra-lateral tissue. The SIR was similarly measured for CBV in same region. FLAIR negative was defined as SIR<1.15, “Low CBV” was defined as CBV SIR <0.5. Results: One hundred eighty two patients were screened and 30 met all study criteria; 21 women, with mean age of 71 (± 16) years and median NIHSS 18 (IQR 9-22). Using linear regression analysis, CBV SIR was associated with FLAIR SIR (p <0.049). In the 0-3hr time window, overall CBV was not associated with FLAIR hyperintensity. However, in the 3-7.5hr time window, patients with negative FLAIR were more likely to have low CBV and conversely, patients with positive FLAIR were more likely to have normal CBV. Conclusion: CBV likely mediates FLAIR hyperintensity in 3-7.5hr of stroke onset but it has less impact on FLAIR hyperintensity in the first 3 hours of AIS. Low CBV could be a potential surrogate imaging biomarker in addition to FLAIR hyperintensity in the early phase of AIS.

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Cerebral blood volume Alberta Stroke Program Early Computed Tomography Score predicts intracranial hemorrhage after thrombectomy in patients with acute ischemic stroke in an extended time window

Acta Radiologica ◽

10.1177/0284185121990843 ◽

2021 ◽

pp. 028418512199084

Author(s):

Yue-Zhou Cao ◽

Lin-Bo Zhao ◽

Zhen-Yu Jia ◽

Qiang-Hui Liu ◽

Xiao-Quan Xu ◽

...

Keyword(s):

Computed Tomography ◽

Ischemic Stroke ◽

Acute Ischemic Stroke ◽

Blood Volume ◽

Intracranial Hemorrhage ◽

Cerebral Blood Volume ◽

Time Window ◽

Univariate Analysis ◽

Lower Probability ◽

Extended Time

Background Higher baseline Alberta Stroke Program Early Computed Tomography Score (ASPECTS) was associated with a lower probability of hemorrhagic transformation in patients with acute ischemic stroke (AIS). Purpose To investigate the predictive value of cerebral blood volume (CBV)-ASPECTS of intracranial hemorrhage (ICH) in AIS treated with thrombectomy selected by computed tomographic perfusion (CTP) in an extended time window. Material and Methods A total of 91 consecutive patients with AIS with large vessel occlusion in the anterior circulation after thrombectomy in an extended time window were enrolled between January 2018 and September 2019. ICH was diagnosed according to Heidelberg Bleeding Classification. CBV-ASPECTS was assessed by evaluating each ASPECTS region for relatively low CBV value compared with the mirror region in the contralateral hemisphere. Demographic characteristics, clinical data, CBV-ASPECTS, and procedure process and results were compared between patients with ICH and those without. Results ICH occurred in 31/91 (34.1%) patients with AIS. Symptomatic ICH (sICH) was observed in 4 (4.4%) patients, while asymptomatic ICH (aICH) was seen in 27 (29.7%). In univariate analysis, both ICH and aICH were associated with high admission NIHSS score ( P<0.001 and P<0.001, respectively), more passes of retriever ( P = 0.007 and P = 0.019, respectively), low NCCT-ASPECTS ( P = 0.013 and P = 0.034, respectively), and low CBV-ASPECTS ( P < 0.001 and P < 0.001, respectively). After multivariable analysis, low CBV-ASPECTS remained an independent predictor of ICH (odds ratio [OR] 0.521, 95% confidence interval [CI] 0.371–0.732, P < 0.001) and aICH (OR 0.532, 95% CI 0.376–0.752, P < 0.001), respectively. Conclusion Low CBV-ASPECTS independently predicts ICH in patients with AIS treated with thrombectomy selected by CTP in an extended time window.

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Intra-domain task-adaptive transfer learning to determine acute ischemic stroke onset time

Computerized Medical Imaging and Graphics ◽

10.1016/j.compmedimag.2021.101926 ◽

2021 ◽

Vol 90 ◽

pp. 101926

Author(s):

Haoyue Zhang ◽

Jennifer S Polson ◽

Kambiz Nael ◽

Noriko Salamon ◽

Bryan Yoo ◽

...

Keyword(s):

Ischemic Stroke ◽

Acute Ischemic Stroke ◽

Transfer Learning ◽

Onset Time ◽

Stroke Onset

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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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Abstract TP38: Core Growth Speed as a Marker of Collateral Circulation Status in Acute Ischemic Stroke with Known Onset Time

Stroke ◽

10.1161/str.48.suppl_1.tp38 ◽

2017 ◽

Vol 48 (suppl_1) ◽

Author(s):

Laura Blanco-García ◽

Elisa Cortijo ◽

Mercedes De Lera ◽

Ana Calleja ◽

María Usero ◽

...

Keyword(s):

Ischemic Stroke ◽

Acute Ischemic Stroke ◽

Collateral Circulation ◽

Cerebral Blood Volume ◽

Onset Time ◽

Growth Speed ◽

Infarct Core ◽

Anterior Circulation ◽

Unaffected Side ◽

Core Volume

Objective: We aimed to evaluate the parameter core growth speed (CGS) as a marker of collateral circulation status (CC) in acute ischemic stroke, and to compare it with other brain perfusion-derived markers of collateral capacity. Methods: We retrospectively studied acute ischemic stroke patients who were evaluated with urgent computed tomography perfusion (CTP) and CT angiography. Inclusion criteria comprised known time of onset and anterior circulation proximal occlusion. Collateral circulation was assessed on CTP-source images and rated as poor (0-1) vs. good (2-3) following a previously published scale. CTP maps were computed using Neuroscape 2.0 software by Olea Medical. Infarct core volume was calculated as the brain tissue with >70% reduction in cerebral blood flow (CBF) as compared to the unaffected side. CGS was obtained by dividing core volume by the time from stroke onset to CTP acquisition. Relative cerebral blood volume (rCBV), relative CBF, and hypoperfusion index ratio (HIR = Tmax>10s/Tmax>6s) were used as comparators. Results: We included 41 patients (mean age 71 years; median NIHSS 17; median onset-CTP time 150 minutes). We observed a positive correlation between CGS and HIR (ρ= 0.517 p< 0.001), and negative correlations between rCBV and CGS (ρ= -0.669 p<0.0001), and rCBF and CGS (ρ= -0.749 p<0.0001). Collateral circulation was categorized as poor or good in 15 and 26 patients respectively. A gradual descend in CGS was seen as CC improved (p=0.0005). A logistic regression model adjusted by rCBV, rCBF and HIR identified CGS as independently associated with CC. The association of CGS with good CC in a ROC curve was highly significant (p=0.002, area under the curve 0.8). Conclusion: Core growth speed is robustly associated with collateral circulation status. This parameter can be directly obtained from infarct core volume without the need to process other perfusion or angiographic images, if the time of onset is well known.

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Factors that influence clinicians’ decisions to offer intravenous alteplase in acute ischemic stroke patients with uncertain treatment indication: Results of a discrete choice experiment

International Journal of Stroke ◽

10.1177/1747493017690755 ◽

2017 ◽

Vol 13 (1) ◽

pp. 74-82 ◽

Cited By ~ 1

Author(s):

Aoife De Brún ◽

Darren Flynn ◽

Laura Ternent ◽

Christopher I Price ◽

Helen Rodgers ◽

...

Keyword(s):

Decision Making ◽

Ischemic Stroke ◽

Acute Ischemic Stroke ◽

Discrete Choice Experiment ◽

Discrete Choice ◽

Choice Experiment ◽

Onset Time ◽

Stroke Onset ◽

Related Factors ◽

Intravenous Alteplase

Background Treatment with intravenous alteplase for eligible patients with acute ischemic stroke is underused, with variation in treatment rates across the UK. This study sought to elucidate factors influencing variation in clinicians’ decision-making about this thrombolytic treatment. Methods A discrete choice experiment using hypothetical patient vignettes framed around areas of clinical uncertainty was conducted with UK-based clinicians. Mixed logit regression analyses were conducted on the data. Results A total of 138 clinicians completed the discrete choice experiment. Seven patient factors were individually predictive of increased likelihood of immediately offering IV alteplase (compared to reference levels in brackets): stroke onset time 2 h 30 min [50 min]; pre-stroke dependency mRS 3 [mRS 4]; systolic blood pressure 185 mm/Hg [140 mm/Hg]; stroke severity scores of NIHSS 5 without aphasia, NIHSS 14 and NIHSS 23 [NIHSS 2 without aphasia]; age 85 [68]; Afro-Caribbean [white]. Factors predictive of withholding treatment with IV alteplase were: age 95 [68]; stroke onset time of 4 h 15 min [50 min]; severe dementia [no memory problems]; SBP 200 mm/Hg [140 mm/Hg]. Three clinician-related factors were predictive of an increased likelihood of offering IV alteplase (perceived robustness of the evidence for IV alteplase; thrombolyzing more patients in the past 12 months; and high discomfort with uncertainty) and one with a decreased likelihood (high clinician comfort with treating patients outside the licensing criteria). Conclusions Both patient- and clinician-related factors have a major influence on the use of alteplase to treat patients with acute ischemic stroke. Clinicians’ views of the evidence, comfort with uncertainty and treating patients outside the license criteria are important factors to address in programs that seek to reduce variation in care quality regarding treatment with IV alteplase. Further research is needed to further understand the differences in clinical decision-making about treating patients with acute ischemic stroke with IV alteplase.

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Comparative evaluation of cerebral blood volume and cerebral blood flow in acute ischemic stroke by using perfusion-weighted MR imaging and spect

Acta Radiologica ◽

10.1034/j.1600-0455.2002.430404.x ◽

2002 ◽

Vol 43 (4) ◽

pp. 365-370 ◽

Cited By ~ 8

Author(s):

J. H. Kim ◽

E.-J. Lee ◽

S.-J. Lee ◽

N.-C. Choi ◽

B. H. Lim ◽

...

Keyword(s):

Blood Flow ◽

Cerebral Blood Flow ◽

Ischemic Stroke ◽

Mr Imaging ◽

Acute Ischemic Stroke ◽

Blood Volume ◽

Comparative Evaluation ◽

Cerebral Blood Volume

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Cerebral Hemodynamics in Human Acute Ischemic Stroke: A Study with Diffusion- and Perfusion-Weighted Magnetic Resonance Imaging and SPECT

Journal of Cerebral Blood Flow & Metabolism ◽

10.1097/00004647-200006000-00003 ◽

2000 ◽

Vol 20 (6) ◽

pp. 910-920 ◽

Cited By ~ 63

Author(s):

Yawu Liu ◽

Jari O. Karonen ◽

Ritva L. Vanninen ◽

Leif Østergaard ◽

Reina Roivainen ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Ischemic Stroke ◽

Magnetic Resonance ◽

Acute Ischemic Stroke ◽

Blood Volume ◽

Cerebral Blood Volume ◽

Acute Stage ◽

Resonance Imaging ◽

Relative Cerebral Blood Volume ◽

Ischemic Tissue

Nineteen patients with acute ischemic stroke (<24 hours) underwent diffusion-weighted and perfusion-weighted (PWI) magnetic resonance imaging at the acute stage and 1 week later. Eleven patients also underwent technetium-99m ethyl cysteinate dimer single-photon emission computed tomography (SPECT) at the acute stage. Relative (ischemic vs. contralateral control) cerebral blood flow (relCBF), relative cerebral blood volume, and relative mean transit time were measured in the ischemic core, in the area of infarct growth, and in the eventually viable ischemic tissue on PWI maps. The relCBF was also measured from SPECT. There was a curvilinear relationship between the relCBF measured from PWI and SPECT ( r = 0.854; P < 0.001). The tissue proceeding to infarction during the follow-up had significantly lower initial CBF and cerebral blood volume values on PWI maps ( P < 0.001) than the eventually viable ischemic tissue had. The best value for discriminating the area of infarct growth from the eventually viable ischemic tissue was 48% for PWI relCBF and 87% for PWI relative cerebral blood volume. Combined diffusion and perfusion-weighted imaging enables one to detect hemodynamically different subregions inside the initial perfusion abnormality. Tissue survival may be different in these subregions and may be predicted.

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