RPS 211 - Modern imaging in stroke

Author Block: C. Khan, B. Roozenbeek, P. J. van Doormaal, A. Van Der Lugt, D. Bos, CONTRAST consortium; Rotterdam/NL
Purpose: Endovascular thrombectomy (EVT) has reduced disability in ischemic stroke patients, but significant outcome variability persists despite recanalisation. It is unknown whether CT-perfusion can improve functional outcome prediction. This study investigates the prognostic value of baseline CT-perfusion parameters for functional independence in acute ischemic stroke patients treated with thrombectomy in MR PREDICTS.
Methods or Background: Ischemic patients treated with EVT from MR CLEAN NOIV, MR CLEAN MED, and MR CLEAN LATE, and with available baseline CT-perfusion were included. Post-processing was performed using Siemens syngo.via.VB80C to retrieve penumbra (cerebral blood flow<27ml/100g/min) and ischemic core volumes (cerebral blood volume (CBV)<1.2ml/100ml), hypoperfusion intensity ratio (brain tissue volume Tmax>10s / brain tissue volume Tmax>6s) and CBV-index (average CBV in Tmax>6s within ischemic hemisphere / average CBV in Tmax≤4s tissues). Primary outcome was functional independence defined as modified Rankin Scale (mRS) 0-2 versus 3-6 at 90 days. Secondary outcome was functional outcome using ordinal mRS (0-6). The prediction model MR PREDICTS was used as benchmark and CT-perfusion parameters were added and compared to the benchmark using likelihood ratio tests. Bootstrapping was used for internal validation. Discrimination was reported using (ordinal) c-statistic.
Results or Findings: A total of 354 patients were included. Ischemic core significantly improved the benchmark model (p<0.05) and increased the c-statistic for functional independence (0.81, 95% CI 0.77–0.86 versus 0.80, 95% CI 0.76–0.84) and ordinal functional outcome (0.73, 95% CI 0.70–0.76 versus 0.72, 95% CI 0.69–0.75). CBV-index yielded similar results to ischemic core.
Conclusion: Baseline CT-perfusion may slightly improve the MR PREDICTS model for functional independence and outcome in ischemic stroke patients treated with EVT. Future studies should investigate whether CT-perfusion can improve treatment effect prediction for clinical decision making.
Limitations: This study lacks external validation and CT-perfusion post-processing is vendor specific.
Funding for this study: The MR CLEAN NOIV, MR CLEAN MED, and MR CLEAN LATE trials were supported by the Collaboration for New Treatments of Acute Stroke (CONTRAST) consortium, which is supported by the Netherlands Cardiovascular Research Initiative, an initiative of the Dutch Heart Foundation (CVON2015-01: CONTRAST); the Brain Foundation Netherlands (HA2015.01.06); the Ministry of Economic Affairs by means of the PPP Allowance made available by Top Sector Life Sciences and Health to stimulate public–private partnerships (LSHM17016); and unrestricted funding by Stryker, Medtronic, and Cerenovus. CLEOPATRA study led by Amsterdam UMC, the Netherlands, has contributed to the collection of CTP data and is sponsored by Zorgevaluatie Leading the Change.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: The MR CLEAN NOIV, MR CLEAN MED, and MR CLEAN LATE were approved by the Medical and Ethical Review Committee in the Netherlands as part of the original trial protocols. All patient records and images were anonymised before analysis, and written informed consent was obtained from all patients or their legal representatives.

Author Block: Y. h. Y ou, Y. Xiong, W. Zhu; Wuhan/CN
Purpose: This study aims to evaluate the predictive value of dual-energy CT (DECT) parameters compared to CT perfusion (CTP) for hemorrhagic transformation (HT) after endovascular therapy (EVT) in acute ischemic stroke (AIS) patients, and to analyze their correlations with clinical parameters.
Methods or Background: We included 112 AIS patients who underwent scanning on Revolution CT Power and received EVT. Based on post-treatment HT occurrence, patients were divided into HT (n=25; age 42-89; male=14) and non-HT groups (n=87; age 31-87; male=54). DECT parameters [effective atomic number (Effective-Z), iodine concentration (Iodine Water)], CTP parameters [cerebral blood flow<30% volume (CBF<30%), time to maximum>6s volume (Tmax>6s)], and clinical data were collected. Univariate and multivariate binary logistic regression were used to identify independent predictors and construct prediction models. Predictive performance was evaluated using receiver operating characteristic (ROC) curve analysis.
Results or Findings: Significant intergroup differences (P<0.05) were observed in Effective-Z, Iodine Water, CBF<30% volume, Tmax>6s volume, age, diabetes history, stroke history, prior endovascular intervention/surgery, modified Rankin Scale (mRS) score, and Activities of Daily Living (ADL) score. Multivariate analysis identified Effective-Z, age, diabetes history, and mRS score as independent predictors of HT. ROC analysis showed comparable predictive efficacy between DECT parameters (Effective-Z, AUC=0.67; Iodine Water, AUC=0.66) and CTP parameters (CBF<30% volume, AUC=0.71; Tmax>6s volume, AUC=0.65). The combined model integrating DECT parameters with clinical independent predictors demonstrated optimal predictive performance (AUC=0.80). DECT parameters significantly correlated with both CTP parameters and neurological function scores in Spearman analysis.
Conclusion: DECT parameters demonstrate predictive capability for HT post-EVT in AIS patients comparable to CTP. The combined model incorporating DECT parameters and clinical factors provides the highest predictive value, serving as an effective tool for hemorrhage risk assessment.
Limitations: Not applicable.
Funding for this study: No funding was provided for this study.
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information:

Author Block: S. T. Gunda, J. H-Y. Yip, V. T-K. Ng, Z. Chen, X. Han, J. Qu, X. Chen, M. Y-C. Pang, M. Ying; Kowloon/HK
Purpose: Stroke poses a serious public health burden due to high morbidity and mortality worldwide. Ultrasonography has advanced over recent years, and emerging techniques such as three-dimensional(3D) and arterial stiffness analysis may provide new insights on stroke risk biomarkers, critical for preventative and therapeutic management. This study compared cerebral arteries’ morphological and haemodynamic features between post-stroke patients and non-stroke (controls) as assessed by novel ultrasonography techniques.
Methods or Background: A cross-sectional study involving post-stroke patients and age-matched (controls) aged 50 yrs and above was conducted. Novel ultrasonography applications, including auto CIMT, 3D, and arterial stiffness analysis assessed extracranial cerebral arteries’ morphology and hemodynamic features across the two groups, whereas transcranial color-coded Doppler ultrasound assessed intracranial hemodynamics.
Results or Findings: A total of 124 participants (post-stroke, n=57 and controls, n=67) were enrolled. The carotid beta-stiffness index (CAS β), elastic modulus (CAS kPa), and pulse wave velocity (CAS PWV) were significantly higher in post-stroke patients compared to controls (15.8±26.7 vs. 9.3±7.7, 208.9±333 kPa vs. 123.7±112 kPa, and 7.8±3.9 m/s vs. 6.5±2.2 m/s, all (p<0.05)), respectively. Conversely, carotid compliance and distensibility coefficient were higher in non-stroke (all p<0.05). However, no between group difference in 3D lumen volume stenosis was observed suggesting stenosis-related hemodynamic failure was unlikely the primary stroke mechanism in this population. Furthermore, post-stroke patients showed reduced cerebral blood flow (all DCCA parameters, ICA EDV, and MCA MFV, all p<0.05).
Conclusion: Our study observed significant differences in cerebral arteries’ morphological and haemodynamic features, with post-stroke patients exhibiting higher arterial stiffness and reduced cerebral blood flow compared to non-stroke individuals. Reference values for 3D ultrasound-based and arterial stiffness features are provided.
Limitations: No limitations identified.
Funding for this study: This research project was supported by a research studentship grant (R006) and a research project fund (P0035203) of The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR, China.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: The study was approved by the Institutional Review Board (or Ethics Committee) of The Hong Kong Polytechnic University (HSEARS20220714001)

Author Block: S. De Gracia Nájera, E. Saureu Rufach, C. Miró Ballesté, T. Barrera Yudego, J. A. Rojas Cristancho, G. Mauri Capdevilla, F. Purroy García, R. Mitjana Penella; Lleida/ES
Purpose: Given the low detection rate of cardioembolic sources with transthoracic echocardiography (1%) and the limited availability of transesophageal echocardiography, alternative non-invasive approaches are required for the etiological diagnosis of ischemic stroke, such as extended CT angiography (CTA) without cardiac synchronization performed during the hyperacute phase of stroke.The main objective of this study is to evaluate whether extended CTA provides diagnostic-quality images and enables detection of cardiovascular pathology as a possible stroke etiology. Secondary objectives include evaluating incidental pulmonary or mediastinal findings with potential therapeutic implications for patient management.
Methods or Background: A descriptive, prospective study was conducted including a cohort of 249 patients assessed within the stroke code protocol from January 2024 to September 2025, using extended CTA from the diaphragms upward without cardiac synchronization.
Results or Findings: Out of 249 studies, 223 (89.6%) were considered of moderate or good image quality. A total of 149 patients were diagnosed with ischemic stroke (59.8%). Among this group, 58 were women (38.9%) and 91 were men (61.1%), with an average age of 71 years. In 15 patients (10%), cardiovascular pathology was identified as a potential stroke etiology: 2 with intracardiac thrombus (1.3%), 3 with aortic dissection (2%), 3 with ulcerated plaques in the ascending aorta (2%), and 7 with irregular atherosclerosis in the aortic arch (4.7%). Additionally, concomitant pathologies were observed in 17 patients (11.4%), including pulmonary thromboembolism, neoplastic disease, and infections.
Conclusion: The inclusion of extended CTA in the stroke code protocol may contribute to identifying cardiovascular pathology potentially involved in the etiology of stroke, as well as detecting concomitant conditions that may impact therapeutic management.
Limitations: Not applicable.
Funding for this study: No
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information:

Author Block: T. B. Plojović, D. Janjic, D. Vasin, F. Crnovršanin, N. Spasojević, S. M. Lekic; Belgrade/RS
Purpose: To evaluate the prognostic value of CT perfusion (CTP) parameters in predicting functional outcome after acute ischemic stroke, to compare their performance with the Alberta Stroke Program Early CT Score (ASPECTS) on non-contrast CT (NCCT), and to assess whether collateral scoring on CT angiography (CTA) provides additional predictive value.
Methods or Background: This retrospective study included 122 consecutive patients with acute ischemic stroke admitted to the Emergency Center between January 2023 and December 2024. All patients underwent NCCT, CTA, and CTP as part of the acute stroke protocol. ASPECTS was calculated on NCCT. CTP maps were analyzed for standard thresholds of core (CBF <30%) and penumbra (Tmax >6s). Collateral status was graded on CTA using a semi-quantitative collateral score. Functional outcome was assessed at 90 days using the modified Rankin Scale (mRS), dichotomized into favorable (mRS 0–2) and unfavorable outcome (mRS 3–6).
Results or Findings: NCCT ASPECTS correlated significantly with outcome (p<0.05) but showed limited discriminatory ability (AUC 0.68). CTP-derived parameters, particularly core volume (CBF <30%) and penumbra volume (Tmax >6s), demonstrated stronger correlation with unfavorable outcome (p<0.001) and higher predictive accuracy (AUC 0.82). The addition of CTA collateral score further improved the prognostic model (combined AUC 0.89), outperforming both ASPECTS and CTP alone.
Conclusion: CT perfusion provides superior prognostic value compared with NCCT ASPECTS in predicting functional outcome after acute ischemic stroke. Incorporating CTA collateral assessment further enhances predictive accuracy, underscoring the importance of a multimodal CT approach.
Limitations: Limitations of the study include its retrospective, single-center design, potential software-related variability in perfusion analysis, and the lack of long-term outcome data beyond 90 days
Funding for this study: No funding for this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was conducted in accordance with the Declaration of Helsinki and approved by the Institutional Ethics Committee.

Author Block: P. Gilabert Núñez, H. Cuellar Calabria, M. De Dios, T. Alejandro, A. Roque, A. Calderwood, C. Meza, F. Rizzo, J. Pagola; Barcelona/ES
Purpose: To determine the rate of positive CT results for stroke (CTs+) in patients with a history of atrial fibrillation under a regimen of direct-acting oral anticoagulants (DOAC-AF).
To detect patients with thrombus in the heart or ascending aorta (T+) on a hyperacute cardiac CT in a venous phase.
To find out whether thrombus and left atrial size (LAs) has added value in this clinical presentation.
Methods or Background: DOAC-AF patients admitted to the emergency department with a suspicion of stroke underwent multimodal code stroke CT followed by venous-phase cardiac CT (n=75, 55% men, 81±9 years).
T+ and LAs were correlated with NIHSS (National Institutes of Health Stroke Scale) at admission and discharge and with CTs+, defined as arterial occlusion or ischemia.
Results or Findings: Rates of CTs+ and T+ were 56% and 13%, respectively. Ninety per cent of T+ were CTs+, in contrast to 51% of T- (p=0.02), with sensitivity, specificity, positive and negative predictive values of 21%, 97%, 90% and 49%, respectively. Patients with a severely dilated LAs≥33.2 cm² had rates of S+ and E+ of 90% and 52%, respectively (p=0.002 for comparison with LAs<33.2 cm²).
T+ patients presented with higher NIHSS at baseline (16.5 versus 6;p=0.02). None was discharged with NIHSS-0, compared to 39% of T- (p=0.02).
Conclusion: A modified code stroke CT protocol including a venous-phase cardiac CT allowed for the detection of cardiac thrombi in 13% of patients with a history of medically treated atrial fibrillation. This group showed more severely dilated left atria, presented with higher NIHSS scores at admission and suffered more sequelae than patients without source lesions.
Limitations: The limitatios of this study is that most patients did not undergo transesophageal ultrasound owing to poor clinical condition.
Funding for this study: Funding was provided by European Regional Development Fund 24-00333.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: CEIm EOM(AG)060/2024(6343)

Author Block: E. Hall, B. Hansen, T. Ullberg, J. Wasselius; Lund/SE
Purpose: Subterminus intracranial internal carotid artery (ICA-I) occlusion is an underrecognized stroke subtype which may delay access to endovascular thrombectomy (EVT). This study aimed to:
1) characterise clinical presentation; and
2) assess radiological reporting accuracy in EVT-treated patients with ICA-I occlusions
Methods or Background: EVT-treated patients with ICA-I, ICA terminus (ICA-T), and middle cerebral artery M1 occlusions were identified from a nationwide registry (2016–2022). Outcomes included NIHSS, ASPECT, recanalization success, and 90-day mRS. In a single-center cohort (2016–2025), stroke severity and perfusion deficits were analyzed in relation to anterior and posterior circulation variants, and accuracy of baseline radiology reports was compared with ICA-T and M1 occlusion controls.
Results or Findings: Of 3730 EVT patients, 356 (9.5%) had ICA-I, 657 (17.6%) ICA-T, and 2717 (72.8%) M1 occlusions.
Median preoperative NIHSS was 17 (variance 34) for ICA-I, 19 (variance 25) for ICA-T, and 16 (variance 37) for M1 (p<0.001 between groups). While recanalization rates and 24-hour NIHSS were similar, patients with M1 occlusions had better 90-day outcomes than those with ICA-I or ICA-T occlusions.
Low and high ASPECT were more common for ICA-I occlusions while the intermediate ASPECT values were more common in ICA-T and M1 occlusions (p<0.001).
In ICA-I cases, anterior circulation variants had a greater impact on stroke severity, compared to posterior circulation variants.
Only 29% of ICA-I occlusions were correctly identified in initial radiology reports, compared with 56% for ICA-T and 100% for M1 occlusions.
Conclusion: ICA-I occlusions present with high variability and are often underrecognized on baseline imaging. Greater awareness among radiologists and clinicians is needed to improve diagnostic accuracy and treatment pathways.
Limitations: There is a potential risk of underreporting of ICA-I occlusions due to mild or atypical symptoms.
In Riksstroke, functional outcome is self-reported.
Funding for this study: This study was funded by grants from Teggerstiftelsen to EH, and regional ALF grants to EH, TU and JW, the Crafoord Foundation to JW, VINNOVA to JW, and by SUS Stiftelser & Fonder to JW and BMH. None of the funding bodies had any involvement in the planning of methodology, data retrieval or analysis in the study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: The Swedish Ethical Review Authority approved the study and waived individual informed consent (#2024-03485-01).

Author Block: I. Kiani¹, S. Mohammadzadeh¹, S. Mozaffari¹, H. Mahmoudzadeh¹, D. A. Lakhani², J. Kakadiya³, R. Xu³, A. Dmytriw⁴, V. Yedavalli³; ¹Tehran/IR, ²Morgantown, AL/US, ³Baltimore, MD/US, ⁴Boston, MA/US
Purpose: Despite the widespread success of mechanical thrombectomy (MT) in treating large vessel occlusion acute ischemic stroke, a notable proportion of patients fail to achieve meaningful clinical recovery even after successful recanalization, a phenomenon termed futile recanalization. This study aimed to systematically review and meta-analyze neuroimaging predictors of futile recanalization following MT.
Methods or Background: We conducted a comprehensive systematic review and meta-analysis in accordance with PRISMA guidelines. Eligible studies included adult patients with anterior circulation stroke with large-vessel occlusion who underwent MT, with futile recanalization defined as poor functional outcome despite successful recanalization. Neuroimaging predictors were categorized by imaging modality and pathophysiological domain. Quantitative meta-analyses were performed where data permitted. Quality assessment was conducted using the PROBAST tool.
Results or Findings: A total of 51 studies were included, most of which defined good outcome as a modified Rankin Scale (mRS) score of 0–2 at 90 days. Pooled analysis revealed a significant inverse association between ASPECTS and futile recanalization (OR=0.81; 95% CI: 0.76–0.87), while core volume showed no significant correlation (OR=1.01; 95% CI: 1.00–1.02). Among perfusion and collateral markers, elevated HIR (≥0.3), prolonged peak venous outflow time, low CBV, poor collaterals, and reduced venous outflow were consistently associated with increased odds of FR (ORs up to 8.6). White matter injury, leukoaraiosis, and brain atrophy were strong predictors of FR (ORs up to 10.25).
Conclusion: Neuroimaging findings are helpful for understanding the mechanisms underlying futile recanalization. The integration of quantitative imaging biomarkers into triage protocols has the potential to refine treatment selection and enhance the prediction of outcomes in patients undergoing thrombectomy.
Limitations: Some studies relied on non-standardized or locally defined imaging thresholds, potentially introducing measurement bias. Second, several studies included had retrospective designs and were conducted in single centers.
Funding for this study: Research reported in this publication was supported by the National Institute of General Medical Sciences of the National Institutes of Health under Award Number 5U54GM104942-08. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: