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Background Since proof emerged that IA treatment (IAT) is beneficial for patients with acute ischemic stroke, it has become the standard method of care. Despite these positive results, recovery to functional independence is established in only about one-third of treated patients. The effect of IAT is commonly assessed by functional outcome, whereas its effect on brain tissue salvage is considered a secondary outcome measure (at most). Because patient and treatment selection needs to be improved, understanding the treatment effect on brain tissue salvage is of utmost importance. Objective To introduce infarct probability maps to estimate the location and extent of tissue damage based on patient baseline characteristics and treatment type. Methods Cerebral infarct probability maps were created by combining automatically segmented infarct distributions using follow-up CT images of 281 patients from the MR CLEAN trial. Comparison of infarct probability maps allows visualization and quantification of probable treatment effects. Treatment impact was calculated for 10 Alberta Stroke Program Early CT Score (ASPECTS) and 27 anatomical regions. Results The insular cortex had the highest infarct probability in both control and IAT populations (47.2% and 42.6%, respectively). Comparison showed significant lower infarct probability in 4 ASPECTS and 17 anatomical regions in favor of IAT. Most salvaged tissue was found within the ASPECTS M2 region, which was 8.5% less likely to infarct. Conclusions Probability maps intuitively visualize the topographic distribution of infarct probability due to treatment, which makes it a promising tool for estimating the effect of treatment. [ABSTRACT FROM AUTHOR]

BACKGROUND The value of administering intravenous alteplase before endovascular treatment (EVT) for acute ischemic stroke has not been studied extensively, particularly in non-Asian populations. METHODS We performed an open-label, multicenter, randomized trial in Europe involving patients with stroke who presented directly to a hospital that was capable of providing EVT and who were eligible for intravenous alteplase and EVT. Patients were randomly assigned in a 1:1 ratio to receive EVT alone or intravenous alteplase followed by EVT (the standard of care). The primary end point was functional outcome on the modified Rankin scale (range, 0 [no disability] to 6 [death]) at 90 days. We assessed the superiority of EVT alone over alteplase plus EVT, as well as noninferiority by a margin of 0.8 for the lower boundary of the 95°/o confidence interval for the odds ratio of the two trial groups. Death from any cause and symptomatic intracerebral hemorrhage were the main safety end points. RESULTS The analysis included 539 patients. The median score on the modified Rankin scale at 90 days was 3 (interquartile range, 2 to 5) with EVT alone and 2 (interquartile range, 2 to 5) with alteplase plus EVT. The adjusted common odds ratio was 0.84 (95% confidence interval [CI], 0.62 to 1.15; P = 0.28), which showed neither superiority nor noninferiority of EVT alone. Mortality was 20.5% with EVT alone and 15.8% with alteplase plus EVT (adjusted odds ratio, 1.39; 95% CI, 0.84 to 2.30). Symptomatic intracerebral hemorrhage occurred in 5.9% and 5.3% of the patients in the respective groups (adjusted odds ratio, 1.30; 95% CI, 0.60 to 2.81). CONCLUSIONS In a randomized trial involving European patients, EVT alone was neither superior nor noninferior to intravenous alteplase followed by EVT with regard to disability outcome at 90 days after stroke. The incidence of symptomatic intracerebral hemorrhage was similar in the two groups. (Funded by the Collaboration for New Treatments of Acute Stroke consortium and others; MR CLEAN-NO IV ISRCTN number, ISRCTN80619088.). [ABSTRACT FROM AUTHOR]

BACKGROUND: The effectiveness of endovascular therapy in patients with stroke caused by basilarartery occlusion has not been well studied. METHODS: We randomly assigned patients within 6 hours after the estimated time of onset of a stroke due to basilar-artery occlusion, in a 1:1 ratio, to receive endovascular therapy or standard medical care. The primary outcome was a favorable functional outcome, defined as Hi score of 0 to 3 on the modified Rankin scale (range, 0 to 6, with 0 indicating no disability, 3 indicating moderate disability, and 6 indicating death) at 90 days. The primary safety outcomes were symptomatic intracranial hemorrhage within 3 days after the initiation of treatment and mortality at 90 days. RESULTS: A total of 300 patients were enrolled (154 in the endovascular therapy group and 146 in the medical care group). Intravenous thrombolysis was used in 78.6% of the patients in the endovascular group and in 79.596 of those in the medical group. Endovascular treatment was initiated at a median of 4.4 hours after stroke onset. A favorable functional outcome occurred in 68 of 154 patients (44.2°6) in the endovascular group and 55 of 146 patients (37.7%) in the medical care group (risk ratio, 1.18; 95% confidence interval [CI], 0.92 to 1.50). Symptomatic intracranial hemorrhage occurred in 4.5% of the patients after endovascular therapy and in 0.7% of those after medical therapy (risk ratio, 6.9; 95% CI, 0.9 to 53.0); mortality at 90 days was 38.396 and 43.2%, respectively (risk ratio, 0.87; 95% CI, 0.68 to 1.12). CONCLUSIONS: Among patients with stroke from basilar-artery occlusion, endovascular therapy and medical therapy did not differ significantly with respect to a favorable functional outcome, but, as reflected by the wide confidence interval for the primary outcome, the results of this trial may not exclude a substantial benefit of endovascular therapy. Larger trials are needed to determine the efficacy and safety of endovascular therapy for basilar-artery occlusion. [ABSTRACT FROM AUTHOR]

Background: Both CT angiography and CT perfusion involve the administration and tracking of a contrast medium bolus for different purposes. In this study, we aim to compare the diagnostic accuracy and subjective image quality of CTP-angiographic reconstructions with conventional CTA for occlusion detection in ischemic stroke patients., Methods: In this retrospective study, patients with a final diagnosis of ischemic stroke and who underwent both CTA and CTP from September 2020 up to and including September 2021 were included. CTP-AR was reconstructed from the 1 mm CTP series at the time of maximum arterial inflow. Three reviewers with different levels of experience assessed both CTA and CTP for occlusion detection, expressed certainty, and rated subjective image quality. The reference standard was set at the consensus meeting. Pooled sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. Differences in subjective and objective image quality and certainty were assessed using Kendall's tau correlation and paired samples t-tests., Results: In total, 107/210 included patients had an occlusion based on our reference standard. Pooled sensitivity and specificity for occlusion detection were 90% (95%CI 85-93) and 94% (95%CI 90-97) for CTA, and 89% (95%CI 84-93) and 93% (95%CI 89-96) for CTP-AR, respectively. The pooled certainty did not significantly differ between CTA and CTP-AR (P=.43). The pooled subjective image quality scores significantly differed between CTA and CTP-AR (τ = 0.3, P<.001), where one reviewer rated subjective image quality higher in CTA and two reviewer in CTP-AR., Conclusion: CTP-AR has comparable diagnostic accuracy to conventional CTA imaging for occlusion detection in ischemic stroke patients. Thus, using CTP-AR instead of CTA plus CTP may conserve contrast medium., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: WHZ reports speaker fees from Stryker, Cerenovus, Medtronic, Microvention and Nicolab, and consulting fees from Philips (all paid to institution); chaired the advisory boards of WeTrust (Philips) and ANAIS ([Advanced Neurovascular Access in Combination With a Stent Retriever in Patients With Acute Ischemic Stroke]; Anaconda) (all paid to institution); and chaired the advisory board of InExtremis (CHU Montpellier, Montpellier, France) for which no payments were received. AAP received an institutional grant from Siemens Healthineers and Bayer Healthcare. Other co-authors have nothing to disclose., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: Direct aspiration during endovascular treatment (EVT) for acute ischemic stroke (AIS) patients is safe and effective. The 'Soft torqueable catheter Optimized For Intracranial Access' (Sofia) catheter is commonly used. Data on differences between 5Fr and 6Fr Sofia is limited. Hence, we aimed to compare the clinical, technical, and safety outcomes between both Sofia catheters in AIS patients., Methods: Patients with an intracranial anterior circulation occlusion from the 'Maastricht Stroke Quality-registry' (MaSQ-registry), who underwent EVT for AIS from September 2020 to February 2023, and treated with the Sofia catheter in the first-line technique were included. Outcomes included a shift on the modified Rankin Scale (mRS) score at 90 days, favorable functional outcome (mRS 0-2), first-attempt recanalization rate, and per procedural complications. Multivariable regression analyses were performed with adjustments., Results: Out of 511 registered patients in the MaSQ-registry, 366 patients were included. 281 patients (77 %) were treated with the Sofia 6Fr. No shift towards better outcomes on the ordinal mRS score at 90 days was observed in the Sofia 6Fr group compared to the 5Fr (adjusted common[ac] OR:1.34, 95 %CI:0.70-2.56). Favorable functional outcome (aOR:1.24, 95 %CI:0.49-3.13), and per procedural complications (aOR:1.04, 95 %CI:0.41-2.64) did not differ significantly between Sofia 6Fr and 5Fr. The Sofia 6Fr achieved higher first-attempt successful recanalization rates (53 % versus 34 %; aOR:2.28, 95 %CI:1.11-4.69), and lower total thrombectomy attempts (median:1 versus 2; aβ:-0.63, 95 %CI:-1.21 to -0.05)., Conclusions: The use of 6Fr Sofia aspiration catheter leads in this single-center registry to higher first-attempt successful recanalization rates and fewer thrombectomy attempts compared to the 5Fr Sofia catheter. However, this did not reflect in better clinical outcomes., Competing Interests: Declaration of competing interest WHvZ reports speaker fees from Stryker, Cerenovus, and Nicolab, and consulting fees from Philips (all paid to institution); participated in the advisory boards of WeTrust (Philips) and ANAIS (Anaconda) (all paid to institution); and participated in the advisory boards of InEcxtremis (CHU Montpellier, Montpellier, France) and DISTAL (University Hospital Basel, Basel, Switzerland), studies for which no payments were received. All other authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Purpose: Pre- and post-endovascular treatment (EVT) imaging may aid in predicting functional outcomes in acute middle cerebral artery (MCA) ischemic stroke. Low post-EVT contrast extravasation (CE)-ASPECTS is associated with poor functional outcomes. Besides the MCA regions included in the ASPECTS score, CE may be seen in the mesial temporal (MT) region. In this study, we investigated the frequency and prognostic implication of MT-CE in acute ischemic stroke patients., Methods: Patients with an acute ischemic stroke due to anterior large vessel occlusion who received EVT and post-EVT DECT between 2010 and 2019 were included. Iodine overlay maps of DECT were assessed for the occurrence of CE, using the ASPECTS for occurrence in the MCA region and, calculating a CE-ASPECTS, for whether the MT region was involved. Multivariable linear and logistic regression were used to assess the relationship between involvement of MT-CE and 24-48h NIHSS, mRS, and mortality on a multiple imputed dataset. All models were adjusted significant variables in univariate analyses and for total CE-ASPECTS., Results: 501/651 patients met the inclusion criteria. MT-CE occurred in 97 (19 %) patients, and was more often present in patients with internal carotid artery occlusions. MT-CE was associated with higher NIHSS scores at 24-hours (aβ 2.2, 95 % CI 0.09-4.31), with increased risk of higher mRS scores (acOR 1.88, 95 % CI 1.16-3.06), and with increased risk of mortality (aOR 2.12, 95 % CI 1.16-3.86)., Conclusion: MT-CE is a common finding on post-EVT DECT and is an independent predictor for worse functional outcomes., Competing Interests: Declaration of competing interest W.Z reports consulting fees from Philips, and speaker fees from Stryker, Cerenovus, and Nicolab (all paid to the institution). Moreover, he is participating in the Safety Monitoring Board or Advisory Board of WeTrust (Philips), InEcxtremis (CHU Montpellier), ANAIS (Anaconda), and DISTAL (University of Hospital Basal) studies. A.P received an institutional grant from Siemens Healthineers and Bayer Healthcare. Other co-authors have nothing to disclose., (Copyright © 2024. Published by Elsevier Inc.)

Background: CT perfusion angiographic reconstructions (CTP-AR), derived at the peak arterial inflow, have demonstrated similar diagnostic accuracy to CTA for occlusion detection in the anterior circulation. Colour-coded CTP maps may aid in localizing an occlusion. This study aim to assess the additional value of CTP maps for occlusion detection in ischemic stroke patients assessed with CTA or CTP-AR., Methods: In this single center retrospective study, ischemic stroke patients who underwent both CTA and CTP from September 2020 up to and including September 2021 were included. The 1 mm CTP series at peak arterial inflow corresponds to the CTP-AR. Following the initial assessment of CTA and CTP-AR for occlusion detection, three readers with varying levels of experienced, reassessed the CTA and CTP-AR with access to the color-coded CTP maps. Each CTA and CTP-AR was reviewed by two readers, and certainty of assessment was recorded. The reference standard was determined through a consensus meeting. Differences in certainty were assessed using a t-test for paired samples., Results: Out of 210 patients, 107 patients had an occlusion based on our reference standard. The addition of CTP maps resulted in the finding of 11 (2.6%) additional occlusions out of 420 CTA readings and 9 (2.1%) out of 420 CTP-AR readings, primarily involving distal occlusions. After addition of CTP maps, 7 (1.6%) initial assessments on CTA and 3 (0.7%) initial assessments on CTP-AR were deemed false positive. The overall certainty of all readers significantly (P < 0.001) increased after addition of CTP maps., Conclusion: The usage of CTP maps improved occlusion detection on both CTA and CTP-AR, especially for distal occlusions, and resulted in the increase of the overall level of certainty among readers with varying levels of experience., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Introduction: Despite literature suggesting benefits of a balloon guide catheter (BGC) in stroke thrombectomy, BGCs are not routinely used. This study aimed to get insights in the use of a BGC and the reasons (not) to inflate the balloon., Methods: Data were used of the Maastricht Stroke Quality Registry (MaSQ-Registry), a prospective registry for quality purposes of stroke patients treated between September 2020-February 2023. Additionally, a Dutch nationwide questionnaire was sent among all stroke treating physicians of the Dutch Society of Interventional Radiology (NVIR). Information on the use and reasons for selecting a (non-)BGC and using the BGC was collected., Results: Out of 511 patients registered in the MaSQ-Registry, 458 were included. In 69% (n=317) of the patients a BGC was used; in 68% (n=214) the balloon was not inflated. In 95% of the posterior circulation occlusions a non-BGC was used. In total 47 treating physicians from sixteen stroke centers responded to the questionnaire. 51% (n=24) preferred a non-BGC and 30% (n=14) never used a BGC. 52% and 18% of the BGC-users estimated they inflate the balloon in 80-100% and 0-20% of the times, respectively. The main reasons reported for not inflating the balloon were when the BGC was occlusive (47%) or not placeable (34%) in the carotid artery., Conclusion: This study shows variation in the use of (non-)BGC use with and without inflated balloon among treating physicians in the Netherlands, highlighting current limited consensus regarding the use of (non-)BGCs among stroke treating physicians., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Blood brain barrier disruption (BBBD) can be visualized by contrast extravasation (CE) after endovascular treatment (EVT) in patients with acute ischemic stroke. Elevated blood pressure is a risk factor for BBBD. However, the association between procedural blood pressure and CE post-EVT is unknown., Methods: In this single-center retrospective study, we analyzed 501 eligible patients who received a dual energy CT (DECT) immediately post-EVT for acute ischemic stroke. Procedural blood pressure values (SBP mean , SBP max, SBP max-min, and MAP mean ) were collected. CE was quantified by measuring the maximum parenchymal iodine concentration on DECT iodine overlay map reconstructions. As a measure for the extent of BBBD, we created CE-ASPECTS by deducting one point per hyperdense ASPECTS region on iodine overlay maps. The association between blood pressure and CE was assessed using multivariable linear regression., Results: The procedural SBP mean , SBP max , and MAP mean were 150 ± 26 mmHg, 173 ± 29 mmHg, and 101 ± 17 mmHg, respectively. The median maximum iodine concentration on post-EVT DECT was 1.2 mg/ml (IQR 0.7-2.0), and median CE-ASPECTS was 8 (IQR 5-11). The maximum iodine concentration was not associated with blood pressure. SBP mean , SBP max, and MAP mean were significantly associated with CE-ASPECTS (per 10 mmHg, β = -0.2, 95 % CI -0.31 to -0.09, β = -0.15, 95 % CI -0.25 to -0.06, β = -0.33, 95 % CI -0.49 to -0.17, respectively)., Conclusion: In acute ischemic stroke patients undergoing EVT, particularly in patients achieving successful recanalization, SBP mean , SBP max , and MAP mean are associated with the extent of BBBD on immediate post-EVT DECT, but not with maximum iodine concentration., Competing Interests: Declaration of competing interest W.Z reports consulting fees from Philips, and speaker fees from Stryker, Cerenovus, and Nicolab (all paid to the institution). Moreover, he is participating in the Safety Monitoring Board or Advisory Board of WeTrust (Philips), InEcxtremis (CHU Montpellier), ANAIS (Anaconda), and DISTAL (University of Hospital Basal) studies. A.P received an institutional grant from Siemens Healthineers and Bayer Healthcare. Other co-authors have nothing to disclose., (Copyright © 2024. Published by Elsevier Inc.)

Purpose: After endovascular therapy (EVT) for ischemic stroke, post-EVT CT imaging often shows areas of contrast extravasation (CE) caused by blood brain barrier disruption (BBBD). Before EVT, CT-perfusion (CTP) can be used to estimate salvageable tissue (penumbra) and irrevocably damaged infarction (core). In this study, we aimed to correlate CTP deficits to CE, as a surrogate marker for BBBD, after EVT for ischemic stroke., Methods: In this single center study, EVT patients between 2010 and 2020 in whom both CTP at baseline and DECT post-EVT was performed were included. The presence of core and penumbra on CTP was assessed per ASPECTS region, resulting in a CTP-ASPECTS core and a CTP-ASPECTS core+penumbra . Likewise, CE on DECT was scored per ASPECTS region, resulting in a CE-ASPECTS. Correlation was assessed using Kendall's tau correlation and positive predictive values (PPV) were calculated per ASPECTS region. Bland-Altman plots were created to visualize the agreement between the two scores., Results: 194 patients met our inclusion criteria. The median core and penumbra were 8 cc (IQR 1-25) and 103 cc (IQR 68-141), respectively. The median CTP-ASPECTS core , CTP-ASPECTS core+penumbra , and CE-ASPECTS were 7 (IQR 4-9), 3 (IQR 1-4), and 6 (IQR 4-9), respectively. The correlation between CTP-ASPECTS core and CE-ASPECTS was τ = 0.21, P <.001, and τ = 0.13, P =.02 between CTP-ASPECTS core+penumbra and CE-ASPECTS. Bland-Altman plots showed a mean difference (CTP-ASPECTS minus CE-ASPECTS) of 0.27 (95 %CI -6.7-7.2) for CTP-ASPECTS core and -3.2 (95 %CI -9.7-3.2) for CTP-ASPECTS core+penumbra . The PPVs of the CTP-ASPECTS core and CTP-ASPECTS core+penumbra were highest for the basal ganglia., Conclusion: There is a weak although significant correlation between pre-EVT CTP-ASPECTS and post-EVT CE-ASPECTS. The weak correlation may be attributed to various imaging limitations as well as patient related factors., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: W.Z reports consulting fees from Philips, and speaker fees from Stryker, Cerenovus, and Nicolab (all paid to the institution). Moreover, he is participating in the Safety Monitoring Board or Advisory Board of WeTrust (Philips), InEcxtremis (CHU Montpellier), ANAIS (Anaconda), and DISTAL (University of Hospital Basal) studies. A.P received an institutional grant from Siemens Healthineers and Bayer Healthcare. Other co-authors have nothing to disclose., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Introduction: Hyperglycemia is highly prevalent in patients with acute ischemic stroke and is associated with increased risk of symptomatic intracranial hemorrhage, larger infarct size and unfavorable outcome. Furthermore, glucose may modify the effect of endovascular treatment (EVT) in patients with ischemic stroke. Hyperglycemia might lead to accelerated conversion of penumbra into infarct core. However, it remains uncertain whether hyperglycemia on admission is associated with the size of penumbra or infarct core in acute ischemic stroke. In this study, we aimed to assess the association between hyperglycemia and Computed Tomographic Perfusion (CTP) derived parameters in patients who underwent EVT for acute ischemic stroke., Methods: We used data from the MR CLEAN study (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands). Hyperglycemia was defined as admission serum glucose of >7.8 mmol/L. Dichotomized and quantiles of glucose levels were related to size of core, penumbra and core penumbra ratio. Hypoperfused area is mean transient time 45% higher than that of the contralateral hemisphere. Core is the area with cerebral blood volume of <2 mL/100 g and penumbra is the area with cerebral blood volume > 2 mL/100 g. Core-penumbra ratio is the ischemic core divided by the total volume of hypoperfused tissue (core plus penumbra) multiplied by 100. Adjustments were made for age, sex, NIHSS on admission, onset-imaging time and diabetes mellitus., Results: Hundred seventy-three patients were included. Median glucose level on admission was 6.5 mmol/L (IQR 5.8-7.5 mmol/L) and thirty-five patients (20%) were hyperglycemic. Median core volume was 33.3 mL (IQR 13.6-62.4 mL), median penumbra volume was 80.2 mL (IQR 36.3-123.5 mL) and median core-penumbra ratio was 28.5% (IQR 18.6-45.8%). Patients with hyperglycemia on admission had larger core volumes and core penumbra ratio than normoglycemic patients with a regression coefficient of 15.1 (95% confidence interval (CI), 1.8 to 28.3) and 11.5 (95% confidence interval (CI), 3.4 to 19.7) respectively., Conclusion: Hyperglycemia on admission was associated with larger ischemic core volume and larger core-penumbra ratio in patients with acute ischemic stroke who underwent endovascular treatment., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Background and Purpose: Supervised deep learning is the state-of-the-art method for stroke lesion segmentation on NCCT. Supervised methods require manual lesion annotations for model development, while unsupervised deep learning methods such as generative adversarial networks do not. The aim of this study was to develop and evaluate a generative adversarial network to segment infarct and hemorrhagic stroke lesions on follow-up NCCT scans., Materials and Methods: Training data consisted of 820 patients with baseline and follow-up NCCT from 3 Dutch acute ischemic stroke trials. A generative adversarial network was optimized to transform a follow-up scan with a lesion to a generated baseline scan without a lesion by generating a difference map that was subtracted from the follow-up scan. The generated difference map was used to automatically extract lesion segmentations. Segmentation of primary hemorrhagic lesions, hemorrhagic transformation of ischemic stroke, and 24-hour and 1-week follow-up infarct lesions were evaluated relative to expert annotations with the Dice similarity coefficient, Bland-Altman analysis, and intraclass correlation coefficient., Results: The median Dice similarity coefficient was 0.31 (interquartile range, 0.08-0.59) and 0.59 (interquartile range, 0.29-0.74) for the 24-hour and 1-week infarct lesions, respectively. A much lower Dice similarity coefficient was measured for hemorrhagic transformation (median, 0.02; interquartile range, 0-0.14) and primary hemorrhage lesions (median, 0.08; interquartile range, 0.01-0.35). Predicted lesion volume and the intraclass correlation coefficient were good for the 24-hour (bias, 3 mL; limits of agreement, -64-59 mL; intraclass correlation coefficient, 0.83; 95% CI, 0.78-0.88) and excellent for the 1-week (bias, -4 m; limits of agreement,-66-58 mL; intraclass correlation coefficient, 0.90; 95% CI, 0.83-0.93) follow-up infarct lesions., Conclusions: An unsupervised generative adversarial network can be used to obtain automated infarct lesion segmentations with a moderate Dice similarity coefficient and good volumetric correspondence., (© 2022 by American Journal of Neuroradiology.)

Despite the large overall beneficial effects of endovascular treatment in patients with acute ischemic stroke, severe disability or death still occurs in almost one-third of patients. These patients, who might not benefit from treatment, have been previously identified with traditional logistic regression models, which may oversimplify relations between characteristics and outcome, or machine learning techniques, which may be difficult to interpret. We developed and evaluated a novel evolutionary algorithm for fuzzy decision trees to accurately identify patients with poor outcome after endovascular treatment, which was defined as having a modified Rankin Scale score (mRS) higher or equal to 5. The created decision trees have the benefit of being comprehensible, easily interpretable models, making its predictions easy to explain to patients and practitioners. Insights in the reason for the predicted outcome can encourage acceptance and adaptation in practice and help manage expectations after treatment. We compared our proposed method to CART, the benchmark decision tree algorithm, on classification accuracy and interpretability. The fuzzy decision tree significantly outperformed CART: using 5-fold cross-validation with on average 1090 patients in the training set and 273 patients in the test set, the fuzzy decision tree misclassified on average 77 (standard deviation of 7) patients compared to 83 (±7) using CART. The mean number of nodes (decision and leaf nodes) in the fuzzy decision tree was 11 (±2) compared to 26 (±1) for CART decision trees. With an average accuracy of 72% and much fewer nodes than CART, the developed evolutionary algorithm for fuzzy decision trees might be used to gain insights into the predictive value of patient characteristics and can contribute to the development of more accurate medical outcome prediction methods with improved clarity for practitioners and patients., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: The novel low-profile p48 flow diverter has been designed to treat aneurysms on small vessels of 1.75-3mm. We report our first clinical experiences., Methods: Between March 2018-January 2020, 22 patients with 25 aneurysms were treated with the p48 in 3 centers. One patient had 3 aneurysms covered by one p48 and one patient had 2 aneurysms. There were 5 men, 17 women, with a mean age of 55 years (median 59, range 29-73 years)., Results: In 25 aneurysms, 24 p48 flow diverters were placed. In 1 patient additional coils were placed in the aneurysm. Procedural vessel rupture by the micro guidewire occurred in 2 patients and vessel rupture during p48 balloon dilatation occurred in 1 patient. Overall, the permanent morbidity rate was 13.6% (3 of 22, 95%CI 3.9-34.2%) and mortality was 4.5% (1 of 22, 95%CI <0.01-23.5%). Most complications were procedure-related and not device-specific. Of 22 patients with 25 aneurysms treated with p48, 18 patients with 20 aneurysms had angiographic follow-up after 5-18 months. Of 19 aneurysms, 10 were occluded and 7 showed a remnant. Two aneurysms were open after 6 months. Three aneurysms were still not occluded after 12, 14, and 18 months and these 3 were retreated. Retreatment rate was 16% (3 of 19) and the adequate occlusion rate was 90% (17 of 19)., Conclusions: Treatment of aneurysms in small-caliber vessels with the p48 is feasible and effective but is not without complications. More data is needed to establish indications, safety, and efficacy more accurately.

Background and Purpose: Flow diverters are increasingly used to treat intracranial aneurysms. We report the safety and efficacy of the p64 flow diverter, a resheathable and detachable device for intracranial aneurysms., Materials and Methods: We retrospectively reviewed 108 patients with 109 aneurysms treated with the p64 between March 2014 and July 2019. There were 87 women and 21 men, mean age 57 years. Of 109 aneurysms, 74 were discovered incidentally, 12 were symptomatic, 18 were previously treated, and five were ruptured dissection aneurysms. A total of 10 aneurysms were located in the posterior circulation. The mean aneurysm or remnant size was 8.1 mm., Results: Hemorrhage by perforation with the distal guidewire occurred in two patients with permanent neurological deficits in one. In one patient, acute in-stent occlusion caused infarction with a permanent deficit. Permanent morbidity was 1.9% (2 of 108, 95%CI 0.1-6.9%); there was no mortality. During follow-up, three in-stent occlusions occurred, all asymptomatic. There were no delayed hemorrhagic complications. At six months, 77 of 96 aneurysms (80.2%) were completely occluded, and at last follow-up, this increased to 93 of 96 aneurysms (96.9%). In-stent stenosis at any degree occurred in 11 patients, progressing to asymptomatic complete occlusion in one. In the other patients, stenosis resolved or improved at further follow-up., Conclusion: The p64 offers an effective and safe treatment option. Aneurysm occlusion rate was 97% at last follow-up, mostly achieved with a single device. There were no delayed hemorrhagic complications. Delayed in-stent stenosis infrequently progresses to occlusion but remains a matter of concern.

Background: Atrial fibrillation is an important risk factor for ischemic stroke, and is associated with an increased risk of poor outcome after ischemic stroke. Endovascular thrombectomy is safe and effective in acute ischemic stroke patients with large vessel occlusion of the anterior circulation. This meta-analysis aims to investigate whether there is an interaction between atrial fibrillation and treatment effect of endovascular thrombectomy, and secondarily whether atrial fibrillation is associated with worse outcome in patients with ischemic stroke due to large vessel occlusion., Methods: Individual patient data were from six of the recent randomised clinical trials (MR CLEAN, EXTEND-IA, REVASCAT, SWIFT PRIME, ESCAPE, PISTE) in which endovascular thrombectomy plus standard care was compared to standard care alone. Primary outcome measure was the shift on the modified Rankin scale (mRS) at 90 days. Secondary outcomes were functional independence (mRS 0-2) at 90 days, National Institutes of Health Stroke Scale score at 24 h, symptomatic intracranial hemorrhage and mortality at 90 days. The primary effect parameter was the adjusted common odds ratio, estimated with ordinal logistic regression (shift analysis); treatment effect modification of atrial fibrillation was assessed with a multiplicative interaction term., Results: Among 1351 patients, 447 patients had atrial fibrillation, 224 of whom were treated with endovascular thrombectomy. We found no interaction of atrial fibrillation with treatment effect of endovascular thrombectomy for both primary ( p -value for interaction: 0.58) and secondary outcomes. Regardless of treatment allocation, we found no difference in primary outcome (mRS at 90 days: aOR 1.11 (95% CI 0.89-1.38) and secondary outcomes between patients with and without atrial fibrillation., Conclusion: We found no interaction of atrial fibrillation on treatment effect of endovascular thrombectomy, and no difference in outcome between large vessel occlusion stroke patients with and without atrial fibrillation., (© European Stroke Organisation 2020.)

Treatment selection is becoming increasingly more important in acute ischemic stroke patient care. Clinical variables and radiological image biomarkers (old age, pre-stroke mRS, NIHSS, occlusion location, ASPECTS, among others) have an important role in treatment selection and prognosis. Radiological biomarkers require expert annotation and are subject to inter-observer variability. Recently, Deep Learning has been introduced to reproduce these radiological image biomarkers. Instead of reproducing these biomarkers, in this work, we investigated Deep Learning techniques for building models to directly predict good reperfusion after endovascular treatment (EVT) and good functional outcome using CT angiography images. These models do not require image annotation and are fast to compute. We compare the Deep Learning models to Machine Learning models using traditional radiological image biomarkers. We explored Residual Neural Network (ResNet) architectures, adapted them with Structured Receptive Fields (RFNN) and auto-encoders (AE) for network weight initialization. We further included model visualization techniques to provide insight into the network's decision-making process. We applied the methods on the MR CLEAN Registry dataset with 1301 patients. The Deep Learning models outperformed the models using traditional radiological image biomarkers in three out of four cross-validation folds for functional outcome (average AUC of 0.71) and for all folds for reperfusion (average AUC of 0.65). Model visualization showed that the arteries were relevant features for functional outcome prediction. The best results were obtained for the ResNet models with RFNN. Auto-encoder initialization often improved the results. We concluded that, in our dataset, automated image analysis with Deep Learning methods outperforms radiological image biomarkers for stroke outcome prediction and has the potential to improve treatment selection., (Copyright © 2019. Published by Elsevier Ltd.)

Background and Purpose: Carotid webs are increasingly recognized as an important cause of (recurrent) ischemic stroke in patients without other cardiovascular risk factors. Hemodynamic flow patterns induced by these lesions might be associated with thrombus formation. The aim of our study was to evaluate flow patterns of carotid webs using computational fluid dynamics., Materials and Methods: Patients with a carotid web in the Multicenter Randomized Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke in the Netherlands (MR CLEAN) were selected for hemodynamic evaluation with computational fluid dynamics models based on lumen segmentations obtained from CT angiography scans. Hemodynamic parameters, including the area of recirculation zone, time-averaged wall shear stress, transverse wall shear stress, and the oscillatory shear index, were assessed and compared with the contralateral carotid bifurcation., Results: In our study, 9 patients were evaluated. Distal to the carotid webs, recirculation zones were significantly larger compared with the contralateral bifurcation (63 versus 43 mm 2 , P = .02). In the recirculation zones of the carotid webs and the contralateral carotid bifurcation, time-averaged wall shear stress values were comparable (both: median, 0.27 Pa; P = .30), while transverse wall shear stress and oscillatory shear index values were significantly higher in the recirculation zone of carotid webs (median, 0.25 versus 0.21 Pa; P = .02 and 0.39 versus 0.30 Pa; P = .04). At the minimal lumen area, simulations showed a significantly higher time-averaged wall shear stress in the web compared with the contralateral bifurcation (median, 0.58 versus 0.45 Pa; P = .01)., Conclusions: Carotid webs are associated with increased recirculation zones and regional increased wall shear stress metrics that are associated with disturbed flow. These findings suggest that a carotid web might stimulate thrombus formation, which increases the risk of acute ischemic stroke., (© 2019 by American Journal of Neuroradiology.)

Objective: The putative mechanism for the favourable effect of endovascular treatment (EVT) on functional outcome after acute ischaemic stroke is preventing follow-up infarct volume (FIV) progression. We aimed to assess to what extent difference in FIV explains the effect of EVT on functional outcome in a randomised trial of EVT versus no EVT (MR CLEAN)., Methods: FIV was assessed on non-contrast CT scan 5-7 days after stroke. Functional outcome was the score on the modified Rankin Scale at 3 months. We tested the causal pathway from intervention, via FIV to functional outcome with a mediation model, using linear and ordinal regression, adjusted for relevant baseline covariates, including stroke severity. Explained effect was assessed by taking the ratio of the log odds ratios of treatment with and without adjustment for FIV., Results: Of the 500 patients included in MR CLEAN, 60 died and four patients underwent hemicraniectomy before FIV was assessed, leaving 436 patients for analysis. Patients in the intervention group had better functional outcomes (adjusted common odds ratio (acOR) 2.30 (95% CI 1.62-3.26) than controls and smaller FIV (median 53 vs. 81 ml) (difference 28 ml; 95% CI 13-41). Smaller FIV was associated with better outcome (acOR per 10 ml 0.60, 95% CI 0.52-0.68). After adjustment for FIV the effect of intervention on functional outcome decreased but remained substantial (acOR 2.05, 95% CI 1.44-2.91). This implies that preventing FIV progression explains 14% (95% CI 0-34) of the beneficial effect of EVT on outcome., Conclusion: The effect of EVT on FIV explains only part of the treatment effect on functional outcome., Key Points: • Endovascular treatment in acute ischaemic stroke patients prevents progression of follow-up infarct volume on non-contrast CT at 5-7 days. • Follow-up infarct volume was related to functional outcome, but only explained a modest part of the effect of intervention on functional outcome. • A large proportion of treatment effect on functional outcome remains unexplained, suggesting FIV alone cannot be used as an early surrogate imaging marker of functional outcome.

Background and Purpose: Previous studies indicated that ischemic lesion volume might be a useful surrogate marker for functional outcome in ischemic stroke but should be considered in the context of lesion location. In contrast to previous studies using the ROI approach, which has several drawbacks, the present study aimed to measure the impact of ischemic lesion location on functional outcome using a more precise voxelwise approach., Materials and Methods: Datasets of patients with acute ischemic strokes from the Multicenter Randomized Clinical Trial of Endovascular Therapy for Acute Ischemic Stroke in the Netherlands (MR CLEAN) were used. Primary outcome was functional outcome as assessed by the modified Rankin Scale 3 months after stroke. Ischemic lesion volume was determined on CT scans 3-9 days after stroke. Voxel-based lesion-symptom mapping techniques, including covariates that are known to be associated with functional outcome, were used to determine the impact of ischemic lesion location for outcome., Results: Of the 500 patients in the MR CLEAN trial, 216 were included for analysis. The mean age was 63 years. Lesion-symptom mapping with inclusion of covariates revealed that especially left-hemispheric lesions in the deep periventricular white matter and adjacent internal capsule showed a great influence on functional outcome., Conclusions: Our study confirms that infarct location has an important impact on functional outcome of patients with stroke and should be considered in prediction models. After we adjusted for covariates, the left-hemispheric corticosubcortical fiber tracts seemed to be of higher functional importance compared with cortical lesions., (© 2018 by American Journal of Neuroradiology.)

Background and Purpose: Many studies have emphasized the relevance of collateral flow in patients presenting with acute ischemic stroke. Our aim was to evaluate the relationship of the quantitative collateral score on baseline CTA with the outcome of patients with acute ischemic stroke and test whether the timing of the CTA acquisition influences this relationship., Materials and Methods: From the Multicenter Randomized Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke in the Netherlands (MR CLEAN) data base, all baseline thin-slice CTA images of patients with acute ischemic stroke with intracranial large-vessel occlusion were retrospectively collected. The quantitative collateral score was calculated as the ratio of the vascular appearance of both hemispheres and was compared with the visual collateral score. Primary outcomes were 90-day mRS score and follow-up infarct volume. The relation with outcome and the association with treatment effect were estimated. The influence of the CTA acquisition phase on the relation of collateral scores with outcome was determined., Results: A total of 442 patients were included. The quantitative collateral score strongly correlated with the visual collateral score (ρ = 0.75) and was an independent predictor of mRS (adjusted odds ratio = 0.81; 95% CI, .77-.86) and follow-up infarct volume (exponent β = 0.88; P < .001) per 10% increase. The quantitative collateral score showed areas under the curve of 0.71 and 0.69 for predicting functional independence (mRS 0-2) and follow-up infarct volume of >90 mL, respectively. We found significant interaction of the quantitative collateral score with the endovascular therapy effect in unadjusted analysis on the full ordinal mRS scale ( P = .048) and on functional independence ( P = .049). Modification of the quantitative collateral score by acquisition phase on outcome was significant (mRS: P = .004; follow-up infarct volume: P < .001) in adjusted analysis., Conclusions: Automated quantitative collateral scoring in patients with acute ischemic stroke is a reliable and user-independent measure of the collateral capacity on baseline CTA and has the potential to augment the triage of patients with acute stroke for endovascular therapy., (© 2018 by American Journal of Neuroradiology.)

Background and Purpose: The absence of opacification on CTA in the extracranial ICA in acute ischemic stroke may be caused by atherosclerotic occlusion, dissection, or pseudo-occlusion. The latter is explained by sluggish or stagnant flow in a patent artery caused by a distal intracranial occlusion. This study aimed to explore the accuracy of CTA for differentiating pseudo-occlusion from true occlusion of the extracranial ICA., Materials and Methods: All patients from the Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands (MR CLEAN) with an apparent ICA occlusion on CTA and available DSA images were included. Two independent observers classified CTA images as atherosclerotic cause (occlusion/high-grade stenosis), dissection, or suspected pseudo-occlusion. Pseudo-occlusion was suspected if CTA showed a gradual contrast decline located above the level of the carotid bulb, especially in the presence of an occluded intracranial ICA bifurcation (T-occlusion). DSA images, classified into the same 3 categories, were used as the criterion standard., Results: In 108 of 476 patients (23%), CTA showed an apparent extracranial carotid occlusion. DSA was available in 46 of these, showing an atherosclerotic cause in 13 (28%), dissection in 16 (35%), and pseudo-occlusion in 17 (37%). The sensitivity for detecting pseudo-occlusion on CTA was 82% (95% CI, 57-96) for both observers; specificity was 76% (95% CI, 56-90) and 86% (95% CI, 68-96) for observers 1 and 2, respectively. The κ value for interobserver agreement was .77, indicating substantial agreement. T-occlusions were more frequent in pseudo- than true occlusions (82% versus 21%, P < .001)., Conclusions: On CTA, extracranial ICA pseudo-occlusions can be differentiated from true carotid occlusions., (© 2018 by American Journal of Neuroradiology.)

Background and Purpose: Thrombus CT characteristics might be useful for patient selection for intra-arterial treatment. Our objective was to study the association of thrombus CT characteristics with outcome and treatment effect in patients with acute ischemic stroke., Materials and Methods: We included 199 patients for whom thin-section NCCT and CTA within 30 minutes from each other were available in the Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute ischemic stroke in the Netherlands (MR CLEAN) study. We assessed the following thrombus characteristics: location, distance from ICA terminus to thrombus, length, volume, absolute and relative density on NCCT, and perviousness. Associations of thrombus characteristics with outcome were estimated with univariable and multivariable ordinal logistic regression as an OR for a shift toward better outcome on the mRS. Interaction terms were used to investigate treatment-effect modification by thrombus characteristics., Results: In univariate analysis, only the distance from the ICA terminus to the thrombus, length of >8 mm, and perviousness were associated with functional outcome. Relative thrombus density on CTA was independently associated with functional outcome with an adjusted common OR of 1.21 per 10% (95% CI, 1.02-1.43; P = .029). There was no treatment-effect modification by any of the thrombus CT characteristics., Conclusions: In our study on patients with large-vessel occlusion of the anterior circulation, CT thrombus characteristics appear useful for predicting functional outcome. However, in our study cohort, the effect of intra-arterial treatment was independent of the thrombus CT characteristics. Therefore, no arguments were provided to select patients for intra-arterial treatment using thrombus CT characteristics., (© 2017 by American Journal of Neuroradiology.)

Background and Purpose: Collateral flow is associated with clinical outcome after acute ischemic stroke and may serve as a parameter for patient selection for intra-arterial therapy. In clinical trials, DSA and CTA are 2 imaging modalities commonly used to assess collateral flow. We aimed to determine the agreement between collateral flow assessment on CTA and DSA and their respective associations with clinical outcome., Materials and Methods: Patients randomized in MR CLEAN with middle cerebral artery occlusion and both baseline CTA images and complete DSA runs were included. Collateral flow on CTA and DSA was graded 0 (absent) to 3 (good). Quadratic weighted κ statistics determined agreement between both methods. The association of both modalities with mRS at 90 days was assessed. Also, association between the dichotomized collateral score and mRS 0-2 (functional independence) was ascertained., Results: Of 45 patients with evaluable imaging data, collateral flow was graded on CTA as 0, 1, 2, 3 for 3, 10, 20, and 12 patients, respectively, and on DSA for 12, 17, 10, and 6 patients, respectively. The κ-value was 0.24 (95% CI, 0.16-0.32). The overall proportion of agreement was 24% (95% CI, 0.12-0.38). The adjusted odds ratio for favorable outcome on mRS was 2.27 and 1.29 for CTA and DSA, respectively. The relationship between the dichotomized collateral score and mRS 0-2 was significant for CTA ( P = .01), but not for DSA ( P = .77)., Conclusions: Commonly applied collateral flow assessment on CTA and DSA showed large differences, indicating that these techniques are not interchangeable. CTA was significantly associated with mRS at 90 days, whereas DSA was not., (© 2016 by American Journal of Neuroradiology.)

Background and Purpose: ISAT provided valuable data on patient outcome after endovascular coiling and surgical clipping of ruptured aneurysms. The purpose of this study was to retrospectively review the ≥1-year outcome (in terms of survival, independence, and rebleeding) of patients who were treated in a routine clinical setting., Materials and Methods: Records of patients presenting with an SAH from a ruptured aneurysm between 2000 and 2008 were reviewed. The 403 patients who met the inclusion criteria harbored 443 treated aneurysms; 173 were managed surgically and 230 by endovascular means. Mean clinical follow-up was 33.9 months (range, 12-106 months)., Results: The pretreatment clinical condition according to the HH was significantly better in the surgically treated patients (P = .018). Death occurred in 11.6% after surgery and in 17.4% after endovascular treatment (P = .104). Of the surviving patients in the surgical and endovascular groups, 80.3% and 87.2%, respectively, were able to live independently with grades 0-2 on the mRS (P = .084). Complete aneurysm occlusion was achieved significantly more often after surgical treatment (P < .001). Rebleeding occurred in 3.1% and 2.3% of the patients after surgical treatment and endovascular coiling, respectively. The occurrence of a residual aneurysm at the end of a coiling procedure was significantly related to the frequency of rebleeding (P = .007)., Conclusions: The management of patients with intracranial aneurysms in a routine clinical setting shows good and comparable rates of mortality and independence. Coiling results in lower rates of complete aneurysm occlusion. Postcoiling angiography showing a residual aneurysm is a good predictor of the risk of rebleeding.

Use of the oral antidiabetic drug metformin may cause lactic acidosis, a rare but life-threatening complication, especially in patients with renal function loss. Since intravenously administered iodide-containing contrast media may cause renal function disturbances precautions should be taken in metformin-treated patients for whom a radiological study with intravenous contrast media is considered. In diabetic patients who use metformin a serum creatinine concentration should be measured prior to the radiological study. If the serum creatinine is within normal limits (< 130 mumol/l), metformin can be continued and the examination performed. If the serum creatinine concentration is increased (> or = 130 mumol/l), metformin should be discontinued and replaced by another antidiabetic drug if necessary. The radiological procedure with intravenous contrast media should be postponed for 48 hours. If such a procedure cannot be postponed, additional measures to prevent lactic acidosis (hydration, monitoring of the renal function) should be taken.

Ileus during pregnancy is a rare complication. Malrotation in the adult is an even rarer finding. A case of a woman who developed an ileus in her seventeenth week of pregnancy is presented. At surgery the cause appeared to be a malrotation of the midgut. The incidence and causes of ileus during pregnancy are discussed. Also a short description of the different forms of malrotation are presented. New insights in the etiology of malrotation based on experiments with rats are mentioned.