CTA Source Images as a Predictor of Final Infarct Volume are Time-Dependent

Avascularity on CT angiography source images (CTASI) may better predict final infarct volume in acute stroke as compared to early ischemic changes on non-contract CT. These CTASI findings may represent infarct core and help determine the extent of salvageable tissue. However, the extent of avascularity on CTASI may overestimate infarct volume if transit of contrast is prolonged due to proximal artery occlusion. We present a case where CT-perfusion (CTP) and time-resolved CT-angiography (CTA) identified salvageable tissue thought to be infarcted on CTASI.

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Abstract TP49: Irreversible Ischemic Lesion Characterization: Does CBV_ASPECTS Add to CT_ASPECTS?

Stroke ◽

10.1161/str.47.suppl_1.tp49 ◽

2016 ◽

Vol 47 (suppl_1) ◽

Author(s):

Marina Padroni ◽

Pilar Coscojuela ◽

Sandra Boned ◽

Marc Ribó ◽

Jordi Cabero ◽

...

Keyword(s):

Acute Stroke ◽

Symptom Onset ◽

Cerebral Blood Volume ◽

Ct Perfusion ◽

Infarct Volume ◽

Relevant Information ◽

Artery Occlusion ◽

Carotid Artery Occlusion ◽

Anterior Circulation ◽

Ischemic Lesion

Introduction: The best technique for selecting acute stroke patients for reperfusion therapies is not defined yet. ASPECTS is a useful score for assessing the extent of early ischemic signs in the anterior circulation on non-contrast CT (CT). Cerebral blood volume (CBV) on CT perfusion (CTP) defines the core lesion assumed to be irreversibly damaged. Whether CBV provides additional information over CT in the initial ASPECTS assessment is unknown. We aim to explore the advantages of CBV_ASPECTS over CT_ASPECTS in the prediction of final infarct volume. Methods: Consecutive patients with middle cerebral or internal carotid artery occlusion who underwent endovascular reperfusion treatment according to initial CT_ASPECTS≥7 were studied. CBV_ASPECTS was assessed blindly later-on. Recanalization was defined as TICI2b3. Final infarct volumes were measured on follow-up imaging. We defined an irrelevant ASPECTS difference (IAD) as: CT_ASPECTS - CBV_ASPECTS≤1. Results: Sixty-five patients, mean age 67±14, median NIHSS:16(10-20) were studied. Recanalization rate was: 78.5%. Median CT_ASPECTS was 9(8-10), and CBV_ASPECTS 8(8-10). Mean time from symptom onset to CT was 219±143 min. 50 patients (76.9%) showed an IAD. The ASPECTS difference was inversely correlated to the time from symptom onset to CT (r:-0.36, p<0.01). A ROC curve defined 120 minutes as the best cut-off time point after which the ASPECTS difference becomes irrelevant. The rate of IAD was significantly higher after 120 minutes (89.5% Vs 37.5; p<0.01). CBV_ASPECTS but not CT_ASPECTS correlated to the final infarct (r:-0.33, p<0.01). However, if CT was done >2 hours after symptom onset, then CT_ASPECTS was correlated to final infarct (r:-0.39, p=0.01). No other variables were associated with CT-CBV_ASPECTS difference. Conclusions: In acute stroke patient CBV_ASPECTS correlates with final infarct volume. However, when CT is performed after 120 minutes from symptoms onset CBV_ASPECTS does not add relevant information to CT_ASPECTS.

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Abstract WP49: Defining the Acute Infarct Core with CT Perfusion in Ischemic Stroke: Physiological and Technical Issues

Stroke ◽

10.1161/str.44.suppl_1.awp49 ◽

2013 ◽

Vol 44 (suppl_1) ◽

Author(s):

Christopher D d’Esterre ◽

Enrico Fainardi ◽

Ting Yim Lee

Keyword(s):

Optimal Parameter ◽

Ct Perfusion ◽

Infarct Volume ◽

Mean Transit Time ◽

Reactive Hyperemia ◽

Poor Correlation ◽

Infarct Core ◽

Ischemic Lesion ◽

Ischemic Time ◽

Acute Infarct

Background: CT Perfusion (CTP) defined hemodynamic parameters used to delineate admission infarct core can be affected by truncated data acquisition, recanalization status and reactive hyperemia. We determined the optimal CTP parameter for infarct demarcation while taking these variables into account. Methods: 30 patients had CTP/NCCT scanning within 6 hours of ictus, a 24 hour CTA and an NCCT at 3 months post stroke to define final infarct. Patients were analyzed according to: 1) the percent wash out (truncation) of the ischemic time density curve (ITDC) and 2) recanalization status defined using the 24 hour CTA. CTP functional maps were generated using delay insensitive CTP software (GE Healthcare). For all patients, the total ischemic lesion (infarct+penumbra+benign oligemia) was defined using the contrast delay plus mean transit time map. Cerebral blood flow (CBF), cerebral blood volume (CBV) and the product of CBF and CBV (CBFxCBV) were used to define the infarct core defect, according to established thresholds, and compared with the infarct volume defined on the 3 month NCCT. The coefficients of correlation (R2) of linear regression models were used for the comparisons. Results: R2 values for admission CBF, CBV, and CBFxCBV defect versus final infarct volume for patients with and without truncation of the ITDC were 0.89, 0.49, 0.65 and 0.90, 0.42, 0.68, respectively; while R2 values for patients with and without recanalization at 24 hours were 0.73, 0.33, 0.44 and 0.84, 0.54, 0.45, respectively. In addition, for the recanalization group with and without truncation of the ITDC, R2 for CBF, CBV, CBFxCBV versus final infarct volume were 0.73, 0.12, 0.31 and 0.79, 0.58, 0.56, respectively. Hyperemia, defined as an increase in CBV relative to the contralateral hemisphere, was observed in 30% of patients. Both hyperemia and ITDC truncation led to poor correlation between the CBV defect and NCCT defined infarct volume. Conclusion: CBF is the optimal parameter for determining the size of the acute infarct core as it is not affected by truncation of the ITDC and autoregulatory vasodilation causing reactive hyperemia.

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Infarct Core Reliability by CT Perfusion is a Time‐Dependent Phenomenon

Journal of Neuroimaging ◽

10.1111/jon.12692 ◽

2020 ◽

Vol 30 (2) ◽

pp. 240-245

Author(s):

Sivan‐Hoffmann Rotem ◽

Saban Mor ◽

Buxbaum Chen ◽

Srour Firas ◽

Sprecher Elliot ◽

...

Keyword(s):

Ct Perfusion ◽

Time Dependent ◽

Infarct Core

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Early CT perfusion mismatch in acute stroke is not time-dependent but relies on collateralization grade

Neuroradiology ◽

10.1007/s00234-016-1643-8 ◽

2016 ◽

Vol 58 (4) ◽

pp. 357-365 ◽

Cited By ~ 7

Author(s):

Louisa von Baumgarten ◽

Kolja M. Thierfelder ◽

Sebastian E. Beyer ◽

Alena B. Baumann ◽

Christine Bollwein ◽

...

Keyword(s):

Acute Stroke ◽

Ct Perfusion ◽

Time Dependent

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MiR-29a Knockout Aggravates Neurological Damage by Pre-polarizing M1 Microglia in Experimental Rat Models of Acute Stroke

Frontiers in Genetics ◽

10.3389/fgene.2021.642079 ◽

2021 ◽

Vol 12 ◽

Author(s):

Fangfang Zhao ◽

Haiping Zhao ◽

Junfen Fan ◽

Rongliang Wang ◽

Ziping Han ◽

...

Keyword(s):

Ischemic Stroke ◽

Acute Stroke ◽

Molecular Mechanisms ◽

Infarct Volume ◽

Glutamate Release ◽

Artery Occlusion ◽

Experimental Stroke ◽

Neurological Damage ◽

Stroke Patients ◽

Rat Models

ObjectiveBy exploring the effects of miR-29a-5p knockout on neurological damage after acute ischemic stroke, we aim to deepen understanding of the molecular mechanisms of post-ischemic injury and thus provide new ideas for the treatment of ischemic brain injury.MethodsmiR-29a-5p knockout rats and wild-type SD rats were subjected to transient middle cerebral artery occlusion (MCAO). miR-29a levels in plasma, cortex, and basal ganglia of ischemic rats, and in plasma and neutrophils of ischemic stroke patients, as well as hypoxic glial cells were detected by real-time PCR. The infarct volume was detected by TTC staining and the activation of astrocytes and microglia was detected by western blotting.ResultsThe expression of miR-29a-5p was decreased in parallel in blood and brain tissue of rat MCAO models. Besides, miR-29a-5p levels were reduced in the peripheral blood of acute stroke patients. Knockout of miR-29a enhanced infarct volume of the MCAO rat model, and miR-29a knockout showed M1 polarization of microglia in the MCAO rat brain. miR-29a knockout in rats after MCAO promoted astrocyte proliferation and increased glutamate release.ConclusionKnockout of miR-29a in rats promoted M1 microglial polarization and increased glutamate release, thereby aggravating neurological damage in experimental stroke rat models.

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Abstract 38: Brain CT Perfusion is Superior to Non-contrast CT Aspects in the Evaluation of Hyperacute Infarct Volume

Stroke ◽

10.1161/str.48.suppl_1.38 ◽

2017 ◽

Vol 48 (suppl_1) ◽

Author(s):

Jelle Demeestere ◽

Carlos Garcia-Esperon ◽

Pablo Garcia-Bermejo ◽

Fouke Ombelet ◽

Patrick McElduff ◽

...

Keyword(s):

Computed Tomography ◽

Ischemic Stroke ◽

Ct Perfusion ◽

Infarct Volume ◽

Lesion Volume ◽

Infarct Core ◽

Anterior Circulation ◽

C Statistic ◽

Contrast Ct ◽

Core Volume

Objective: To compare the predictive capacity to detect established infarct in acute anterior circulation stroke between the Alberta Stroke Program Early Computed Tomography Score (ASPECTS) on non-contrast computed tomography (CT) and CT perfusion. Methods: Fifty-nine acute anterior circulation ischemic stroke patients received brain non-contrast CT, CT perfusion and hyperacute magnetic resonance imaging (MRI) within 100 minutes from CT imaging. ASPECTS scores were calculated by 4 independent vascular neurologists, blinded from CT perfusion and MRI data. CT perfusion infarct core volumes were calculated by MIStar software. The accuracy of commonly used ASPECTS cut-off scores and a CT perfusion core volume of ≥ 70 mL to detect a hyperacute MRI diffusion lesion of ≥ 70 ml was evaluated. Results: Median ASPECTS score was 9 (IQR 7-10). Median CT perfusion core volume was 22 ml (IQR 10.4-71.9). Median MRI diffusion lesion volume was 24,5 ml (IQR 10-63.9). ASPECTS score of < 6 had a sensitivity of 0.37, specificity of 0.95 and c-statistic of 0.66 to predict an acute MRI lesion ≥ 70 ml. In comparison, a CT perfusion core lesion of ≥ 70 ml had a sensitivity of 0.76, specificity of 0.98 and c-statistic of 0.92. The CT perfusion core lesion covered a median of 100% of the acute MRI lesion volume (IQR 86-100%). Conclusions: CT perfusion is superior to ASPECTS to predict hyperacute MRI lesion volume in ischemic stroke.

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Abstract WP42: CT Perfusion in Acute Stroke: Substantial Value Beyond Penumbra

Stroke ◽

10.1161/str.44.suppl_1.awp42 ◽

2013 ◽

Vol 44 (suppl_1) ◽

Author(s):

Sarah W Meng ◽

Michael Hewitt ◽

Xiang Liu

Keyword(s):

Acute Stroke ◽

Ct Perfusion ◽

Infarct Volume ◽

Treatment Options ◽

Vascular Occlusion ◽

Diagnostic Sensitivity ◽

Detection Sensitivity ◽

Imaging Protocol ◽

Vascular Thrombosis ◽

Area Of Interest

Purpose: The role of CT Perfusion (CTP) in evaluation of acute stroke remains controversial, especially in determining ischemic penumbra and core infarct. Thus, our institution suspended CTP as part of the acute stroke imaging protocol, and now includes a non-contrast head CT (NCCT) and CT angiography (CTA) of the head and neck. We performed a retrospective review of cases using NCCT, CTA and CTP (CT-CTP) and cases using NCCT and CTA (CT-CTA protocol) at our institution from 2009 to 2011, to assess what, if any, substantial benefit CTP provides in the management of acute stroke. Methods: A total of 758 cases were reviewed, including 375 cases in the CT-CTP protocol and 383 cases in the CT-CTA protocol. Acute infarcts limited to the area covered by CTP were reviewed to compare the diagnostic sensitivity of the two protocols. Followup DWI or NCCT was used as the reference standard for final infarct size. Infarct volume was measured by freehand region of interest measurement. A subset group with final infarct volume > 30ml was also reviewed to explore the detection sensitivity of vascular thrombosis. Results: CTP deficits were reported in all 71 cases with a final infarct volume of 2.8 ml and above. Conversely, in the same category, 23 of 96 (24%) cases were reported as negative with CT-CTA protocol. Of the 10 cases with final infarct volume > 30ml and reported as negative in the CT- CTA protocol, 7of 10 had 2nd or 3rd order vascular thromboses, including 6 cases with infarct volume > 50ml. Only 2 of 45 thromboses were missed in the same category with CT-CTP protocol. Vascular thrombosis was missed in 1 of 10 cases with final infarct volume > 30ml in the CT-CTP protocol where NCCT was reported as negative but had positive CTP deficits. Conclusions: There is a substantially greater detection rate of 2nd and 3rd order vascular thrombosis when CTP is performed, including cases when NCCT is deemed negative. We speculate that a negative NCCT may provide false assurance, but that CTP deficits will guide attention to the area of interest, ultimately increasing detection of vascular occlusion and potentially influencing treatment options in the setting of acute stroke. Additionally, CTP significantly increases the diagnostic sensitivity of acute stroke compared to a combination of NCCT and CTA alone.

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Abstract 2546: Correlation Between Diffusion-weighted Imaging (DWI) Lesion Volume And Alberta Stroke Program Early CT Score (ASPECTS) In Patients Undergoing Acute Stroke Intervention

Stroke ◽

10.1161/str.43.suppl_1.a2546 ◽

2012 ◽

Vol 43 (suppl_1) ◽

Author(s):

Ashutosh P Jadhav ◽

Mouhammad Jumaa ◽

Sayed Zaidi ◽

Carlos L Salinas ◽

Guangming Zhu ◽

...

Keyword(s):

Acute Stroke ◽

Ct Scan ◽

Endovascular Therapy ◽

Infarct Volume ◽

Medical Center ◽

Lesion Volume ◽

Infarct Core ◽

Mri Scan ◽

Occlusion Time ◽

Software Analysis

Background and Purpose: Selection of patients for endovascular acute stroke therapy is evolving into imaging based paradigms that quantitatively assess infarct core thresholds beyond which reperfusion is considered futile or detrimental. We sought to determine whether a correlation exists between pre-intervention infarct volume as measured by DWI MRI and ASPECT scores on CT in patients with acute stroke treated with endovascular therapy who underwent both a pre-procedure MRI scan and a non-contrast CT scan at our institution. Methods: Retrospective review of a prospectively maintained database of acute ischemic strokes treated with endovascular therapy at the University of Pittsburgh Medical Center during 2004-2011. CT-ASPECT scores were prospectively scored by blinded observers. Infarct volume on DWI was determined by automated software analysis (RAPID, n=25 and MIPAV, n=53). The following additional factors were considered: age, NIHSS, time from last seen well (TLSW) to angiography, site of clot occlusion, time between obtaining CT scan and MRI, and parenchymal hematoma (PH) formation. Results: Of 77 patients included in the study, there was a significant negative correlation between CT-ASPECT score and DWI volume size (p<0.0001, by ANOVA). Table 1 outlines the distribution of ASPECTS scores and corresponding mean DWI volumes along with other variables of interest. The mean time between obtaining the CT and MRI scan was 207 minutes. Conclusions: A CT-ASPECT score of 7 or greater corresponds to an average DWI volume of 23 ml or less. Recent studies have shown that a pre treatment DWI volume of <25 ml is predictive of favorable outcomes. Therefore, our findings provide further support of the concept that an ASPECT score cut off of 7 or greater corresponds to core volume thresholds that are predictive of good outcomes following revascularization. Future prospective studies are needed to compare the benefit of CT ASPECTS scores alone versus DWI MRI or other advanced imaging modalities as selection tool for acute stroke endovascular therapy.

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