OBJECTIVE:Immune effector cell-associated neurotoxicity syndrome (ICANS) is the most frequent neurological complication following chimeric antigen receptor (CAR)-T cell therapy. Long-term cognitive effects remain controversial, even in the absence of clinical neurotoxicity. CAR-T cell-associated neurotoxicity often involves the medial temporal lobe (MTL), yet conventional structural magnetic resonance imaging (MRI) frequently remains normal. There is a need for markers of subclinical neurotoxicity that may predict long-term cognitive outcomes. METHODS:Therefore, we established an imaging protocol integrating 3 Tesla (T) and 7 T perfusion and functional connectivity MRI of the MTL in patients receiving CAR-T cells for B cell malignancies. Longitudinal data from four patients is presented here. RESULTS:Two of the four patients developed ICANS (grade 1 and grade 3), and these patients also experienced mild cytokine release syndrome (CRS, grade 1). No structural abnormalities of the MTL were detected at baseline or during follow-up. CAR-T cell expansion varied markedly between patients. Regardless of ICANS, CRS, or CAR-T cell expansion, patients showed increased MTL perfusion and functional connectivity, most prominently at days 10-14. CONCLUSION:These data suggest an early, clinically silent inflammatory response in the MTL with potential implications for long-term cognitive function, which requires further investigation.

Looped-ended braided stents are used in vascular interventions owing to their flexibility, conformability, and self-expansion. However, severe crimping into low-profile delivery catheters concentrates bending, crossing-point migration, and geometric crowding at the terminal crowns, producing stresses that classical uniform-braid models cannot resolve. This limitation is critical for bioabsorbable metallic stents, where excessive end-region stress may compromise deliverability or exceed yield limits. To address this gap, this study develops a large-deformation moving-boundary elastica model that represents the terminal crown as a planar elastica with a moving crossing point and predicts maximum bending stress, radial force, and local geometric jamming. The model was verified against finite element simulations spanning stiffness, pitch angle, wire diameter, loop radius, wire number, and stent diameter, and compared with experimental crimping data for a looped-ended Nitinol braided stent. The predictions showed close agreement with finite element stress and radial-force responses throughout the planar sliding regime and followed the measured force trend before stress-induced martensitic transformation. In high-wire-density configurations, deviations marked the transition to out-of-plane crown buckling and defined the planar model limit. The results establish the looped end as a design-limiting region and provide an end-specific framework for rapid loop-end screening before finite element analysis or prototype testing

MRI-visible perivascular spaces (PVS) are increasingly recognised as markers of compromised brain health, but their quantitative use requires segmentation methods that remain reliable beyond the datasets on which they were developed. Whether current methods meet this requirement remains unclear. To address this gap, we organised the Domain Randomisation PVS (DoRA-PVS) Challenge, a no-data-shared benchmark designed to evaluate out-of-sample PVS segmentation in two settings: an open method track for previously published methods, and a domain randomisation track for new strategies trained exclusively on synthetic data. The testbed comprised 285 images from 12 cohorts, capturing substantial heterogeneity in scanner vendors, field strengths, sequences, imaging protocols, image quality, and participant characteristics. Four teams competed in the first DoRA-PVS Challenge: two in the open method track, one in the domain-randomisation track, and one in both tracks. Preliminary results show that external generalisation is achievable. Across tracks, most methods achieved AUPRC values above random-classifier performance on unseen data, indicating that they could segment PVS beyond their development cohorts. However, this generalisation was not consistent: performance varied substantially across cohorts and evaluation metrics. These preliminary findings shift the central question from whether PVS segmentation methods can generalise at all to whether they can generalise reliably across heterogeneous data. The DoRA-PVS Challenge therefore establishes a rigorous benchmark for assessing out-of-sample robustness and provides a framework for developing PVS segmentation methods that are more consistent across acquisition protocols, populations, and anatomical regions.

Abstract:Middle meningeal artery embolization (MMAE) is a relatively new option for treating chronic subdural hematoma (CSDH). First used in the year 2000 in patients with CSDH and pronounced coagulopathy, today there are several large randomized controlled trials available that report on the efficacy of MMAE. Based on a complex pathophysiological model of CSDH with a focus on inflammation, fibrinolysis, and neoangiogenesis, the MMAE procedure works by blocking the pathological vessels of the CSDH membranes, whose activity prevents resorption of a CSDH. Embolization of the middle meningeal artery requires precise knowledge of the individual anatomy, as severe adverse effects can result from misembolization in critical collaterals. In principle, particles, liquid embolic agents, and coils are available as embolic agents, although particles and liquid embolic agents have been used in the randomized controlled trials published so far. Based on the latest large trials, MMAE is currently recommended by interdisciplinary consensus for patients with de novo CSDH and contraindications to surgical therapy, as well as for patients with recurrence as an adjunct to conventional therapy. Numerous other trials on MMAE have already been registered, so additional data regarding previously unanswered questions are expected in the near future. Key Points:· MMAE is an increasingly important treatment option for CSDH.. · MMAE devascularises pathological haematoma membranes.. · Recent studies show a significant reduction in CSDH recurrences and reoperations following MMAE.. · A thorough understanding of anatomy and careful patient selection are crucial.. Citation Format:· Michael AE, Behme D, Nikoubashman O etal. Embolization of the Middle Meningeal Artery in Chronic Subdural Hematomas. Rofo 2026; DOI 10.1055/a-2851-9748.

In the early phase after mechanical thrombectomy, differentiating between intracranial hemorrhage and contrast medium extravasation on CT imaging remains a major diagnostic challenge. Both can appear hyperdense on standard CT scans, however, they have significantly different clinical implications, particularly regarding anticoagulation decisions. The Virtual Non-Contrast (VNC) technique using photon-counting computed tomography (PCCT), offers the potential to reliably distinguish between blood and iodine-based contrast material in a single scan by virtually removing the iodine component. To evaluate the clinical feasibility and diagnostic performance of the VNC technique in patients after thrombectomy, with focus on the differentiation between hemorrhage and contrast extravasation. In this retrospective study, we analyzed hyperdense areas of 36 patients who underwent PCCT imaging shortly after mechanical thrombectomy. Two experienced neuroradiologists independently assessed the presence of intracranial hemorrhage and residual contrast extravasation using the VNC datasets. Findings, including measured volumes, were compared to follow-up scans. VNC imaging enabled reliable differentiation between hemorrhage and contrast staining. The sensitivity for detecting hemorrhage was 0.93 (25 of 27 patients, confidence interval 0.77–0.98), with a specificity of 100

Zusammenfassung Die Embolisation der Arteria meningea media (MMAE) ist eine relativ neue Option in der Behandlung des chronischen Subduralhämatoms (CSDH). Im Jahr 2000 erstmals bei Patienten mit CSDH unter ausgeprägter Koagulopathie angewendet, liegen aktuell mehrere große randomisierte kontrollierte Studien zur Wirksamkeit der MMAE vor. Ausgehend von einem komplexen pathophysiologischen Modell des CSDH mit Fokus auf Inflammation, Fibrinolyse und Neoangiogenese beruht der Effekt der MMAE auf dem Verschluss von pathologischen Gefäßen der Membranen des CSDH, deren Aktivität die Resorption eines CSDH verhindern. Die Embolisation der A. meningea media erfordert genaue Kenntnisse der individuellen Anatomie, da durch Fehlembolisation bei kritischen Kollateralen schwere unerwünschte Wirkungen folgen können. Als Embolisat stehen prinzipiell Partikel, Flüssigembolisate und Coils zur Verfügung, wobei in den bisher veröffentlichten randomisierten kontrollierten Studien Partikel und Flüssigembolisate zum Einsatz kamen. Basierend auf den letzten großen Studien wird die MMAE im interdisziplinären Konsens aktuell bei Patienten mit de novo CSDH und Kontraindikationen zur operativen Therapie sowie bei Patienten mit Rezidiv als Adjunkt zur herkömmlichen Therapie empfohlen. Eine Vielzahl von weiteren Studien zur MMAE ist bereits registriert, sodass in absehbarer Zeit weitere Daten zu bisher unbeantworteten Fragen erwartet werden können.

Abstract Background and aims To assess early imaging predictors of malignant course of cerebral vein and sinus thrombosis (CVST). Methods Patients admitted with a CVST underwent recurrent CT/MRI to monitor possible space-occupying edema and secondary intracerebral bleeding. Brain scans were scheduled upon admission, after 24 hours, 2 to 4 days and 4 to 7 days. The extent of cerebral edema and secondary bleeding was assessed in relation to the affected cerebral lobe and hemisphere: local (< 25%), partial (25-74%), complete (>=75%). The functional outcome between 3 to 4.5 months served as outcome parameter assessed by the modified Rankin Scale. Cox regression was used for statistical analyses. Results We included 118 patients with cerebral vein (5) and sinus thromboses (113). Their mean age was 46.1 years (SD 18.5), 41 patients were men (34.7%). 54 patients (45.8%) showed some form of edema, 49 patients (41.1%) showed intracerebral hemorrhage. The overall outcome was good. 78 patients (66.1%) had no or no relevant functional deficit. 12 patients (10.2%) died or underwent craniotomy, and 6 patients (5.1%) were left with a severe deficit. The extent of edema in the brain scans performed within 24 hours after the onset of first symptoms (adjusted OR, 1.984; 95% CI, 1.050 to 3.748) and patients’ age (aOR, 1.121; CI 1.023 to 1.229) were predictors of a fatal or very severe clinical course, but not initial bleeding. Conclusions Presence and size of brain edema already within 24 hours of symptoms onset predict poor functional outcome in CVST. Conflict of interest Ferdinand Schüttoff: nothing to disclose

BACKGROUND:Although recently presented randomized trials have failed to prove an overall benefit of mechanical thrombectomy (MT) for patients with medium vessel occlusions (MeVOs), questions remain unanswered, particularly regarding the technology and the role of dedicated small devices. This prospective multicenter, core lab reviewed registry study investigates the efficacy and safety of the APERIO Hybrid used as a first-line device for the treatment of MeVO patients. METHODS:Data from all MeVO patients who underwent MT with the APERIO or APERIO Hybrid17 as a first-line technique were prospectively included. The primary endpoint was the successful recanalization (Thrombolysis In Cerebral Infarction (TICI) 2b/3) after up to three passes with the APERIO without the use of a rescue technique and without any symptomatic intracranial hemorrhage (ICH). RESULTS:134 patients were enrolled from 10 stroke centers. The primary endpoint was reached in 97 patients (81.5%, 95% CI 74.5% to 88.5%). In patients who failed the primary endpoint, TICI 2b/3 was reached with 4 to 6 APERIO passes in 4 patients (3.3%) and with other techniques in 18 patients (15%). Overall recanalization success was 95.8%. TICI 2b/3 with APERIO Hybrid was achieved after the first pass in 76 patients (63.9%), in 23 (19.3%) after 2 passes, and in 1 patient (0.8%) after 3 passes. Modified Rankin Scale (mRS) 0-2 at 90 days was reached by 79.0% of the patients. Symptomatic ICH occurred in no patients, asymptomatic ICH in 16 (13.5%), and subarachnoid hemorrhage in 15 patients (12.6%). CONCLUSION:APERIO and APERIO Hybrid17 have been proven to be both safe and effective first-line devices for MT in MeVO stroke at different centers and with high rates of successful recanalization.

Introduction:Post-dural puncture headache is a well-recognized complication of neuraxial anesthesia caused by cerebrospinal fluid leakage and intracranial hypotension. Although usually self-limiting, persistent post-dural puncture headache may rarely be complicated by cranial nerve palsy. Case Presentation:We report the case of a 33-year-old postpartum woman who developed severe orthostatic headache after apparently uncomplicated epidural labor analgesia, followed by neck stiffness, auditory pressure, and horizontal diplopia due to abducens nerve palsy. Initial cranial computed tomography was unremarkable. Because symptoms persisted despite conservative therapy, magnetic resonance imaging of the brain and spine was performed and demonstrated findings consistent with intracranial hypotension and persistent spinal cerebrospinal fluid leakage. On postpartum day 15, a targeted epidural blood patch was performed under computed tomography guidance at the suspected leak site. This resulted in rapid clinical improvement, with complete resolution of symptoms within 2 weeks. Conclusion:This case highlights a rare neurological complication of post-dural puncture headache and supports the use of image-guided epidural blood patch in selected refractory cases.

The Contour Neurovascular System (CNS) is a novel intrasaccular flow disruptor for the endovascular treatment of wide-necked aneurysms. While more longitudinal studies are needed to fully assess its efficacy, initial study results over the past few years have been promising. However, no studies have yet assessed the CNS’s robustness to deformation over time, and few have assessed its effect on the morphology of intracranial aneurysms. Thirteen IAs were retrospectively analyzed using co-registered 3D meshes from serial imaging (2–5 scans per patient, up to 26 months of follow-up). Morphological parameters of the ostium and CNS were compared across defined time points. Intra-patient variance was also assessed through scans taken on the same day, and morphology was correlated with treatment outcome. Significant postprocedural changes were observed in the ostium’s ellipticity index (EI; Δ = −0.07 ±0.06, p = 0.01, d = −1.18) and neck circularity index (NCI; Δ = +0.04 ±0.04, p = 0.04, d = 0.90). No statistically significant long-term changes were detected for either the ostium or CNS. Most variations were within intra-patient variance, and many measured deformations were below imaging resolution (0.16−0.47 mm). No correlation was found between recurrence and morphology. Only immediate postprocedural shape changes of the ostium were significant. No measurable long-term deformation of the CNS or ostium was observed. The CNS appears morphologically stable, though larger, high-resolution studies are needed to confirm these findings.

Intracranial aneurysms (IAs), characterized by unpredictable growth and risk of rupture, are a major cause of stroke and can lead to life-threatening hemorrhages with high mortality and long-term disability. With aging populations, the incidence and overall burden of cerebrovascular diseases are expected to increase, highlighting the need for scalable approaches to analyze complex medical data and improve population-level understanding of these conditions. While digital twins and deep learning offer promising avenues for improving diagnosis, prognosis, and treatment, their effectiveness is limited by the scarcity of large-scale, high-quality medical data and corresponding labels. We present Synthetic VAsculature (SynVA), a modular toolkit for vascular mesh generation and anatomically consistent aneurysm synthesis. SynVA combines novel flow-matching-based methods for generating healthy vessel meshes with learning-based approaches for anatomy-conditioned aneurysm mesh generation - aneurysms are computed from pre-existing vascular geometries rather than being generated in isolation. In addition, we introduce the SynVA procedural model for vascular and aneurysm synthesis based solely on physiological principles and statistical priors, which enables the generation of large-scale datasets (e.g., for the training of mesh-based generative models). To this end, we release a dataset of 50,000 fully labeled mesh samples for a variety of downstream vision tasks, such as semantic segmentation. Extensive quantitative and qualitative evaluations demonstrate that SynVA generates realistic vessel geometries and anatomically plausible aneurysms. Specifically, our experiments indicate that some methods produce aneurysm shapes more aligned with expert human perception while others perform better on quantitative similarity metrics with reconstructions of real aneurysms.

ABSTRACT:Using intravenous contrast, photon-counting computed tomography angiography (PCCT-A) provides detailed images of intracranial vessels. We report a case in which PCCT-A revealed a 1.5 mm aneurysm at the bifurcation of the middle cerebral artery that was not seen on magnetic resonance angiography. This case highlights the clinical value of PCCT-A in noninvasively detecting small intracranial aneurysms.

BACKGROUND:Mechanical thrombectomy for the treatment of acute ischemic stroke has undergone relevant technical improvements over recent years. However, distal emboli and incomplete reperfusion after mechanical thrombectomy are still shortcomings in the care of patients with endovascular acute ischemic stroke. The NeVa NET 5.5 thrombectomy device (Vesalio, Nashville, Tennessee, USA) is the first stent retriever featuring an integrated clot micro-filtration system, aiming to enhance first pass efficacy and reduce distal embolization. This study evaluates the safety and efficacy of the NeVa NET 5.5 thrombectomy device. METHODS:Patients with acute anterior circulation occlusions and vessel diameters >2 mm treated with the NeVa NET 5.5 stent retriever as a first-line approach were retrospectively included in this study. Data were collected from three European comprehensive stroke centers between October 2022 and April 2024. Patient data, occlusion details, clinical outcomes, and procedure-related parameters were analyzed. RESULTS:A total of 51 patients were included. The most common occlusion locations were the internal carotid artery terminus and intradural internal carotid artery (70.6%). The mean±SD clot length was 25.1±13.3 mm (range 4-50 mm). First pass reperfusion (eTICI 2b-3) was achieved in 78.5%, with a final reperfusion rate of eTICI 2b-3 in 98.1%. Distal embolization in new territories occurred in 3.9%. No device-related adverse events were reported, and procedure-related adverse events occurred in 7.6% of the overall included cases. CONCLUSION:The NeVa NET 5.5 stent retriever has a high first pass reperfusion rate in large vessel occlusions of the anterior circulation, with a good safety profile and low rate of distal embolization.

Background:Computed tomography perfusion (CTP) is frequently used for the rapid assessment of suspected acute ischemic stroke (AIS). However, small lacunar infarcts often remain undetected by automated software, leading to false negatives and additional imaging. We compared the specificity of two commonly used CTP software packages in patients without evidence of stroke on follow-up diffusion-weighted imaging (DWI). Methods:In this single-center retrospective study, 58 consecutive patients with suspected AIS but negative follow-up DWI-MRI were included. All patients underwent CTP on the same scanner. Perfusion data were processed using (1) syngo.via (Siemens Healthcare) with three parameter settings-A: CBV < 1.2 mL/100 mL, B: additional smoothing filter, and C: rCBF <30%-and (2) Cercare Medical Neurosuite (CMN). Software-reported ischemic core volumes were compared with the MRI findings. Results:CMN showed the highest specificity, indicating zero infarct volume in 57/58 patients (98.3%). Conversely, all three syngo.via settings produced false-positive ischemic cores, with median volumes ranging from 21.3 mL (setting C) to 92.1 mL (setting A). Only syngo.via setting C reported zero infarct volume in some patients, yet still showed substantial overestimation (maximum 207.9 mL). Conclusion:Our findings underscore the significant variability in the ability of different CTP software packages to reliably rule out small (lacunar) infarcts. CMN demonstrated good specificity, suggesting that dependable CTP-based stroke exclusion is achievable with advanced post-processing. High specificity could reduce reliance on follow-up MRI in acute stroke pathways if validated, thereby improving resource allocation and patient throughput.

Small intracranial aneurysms (SIAs) (<5 mm) are increasingly detected due to advanced imaging, but predicting rupture risk remains challenging. Rupture, though rare, can cause devastating subarachnoid hemorrhage. This study analyzed 141 SIAs (101 unruptured, 40 ruptured) using semi-automatic morphological analysis and high-resolution, image-based blood flow simulations from 3D rotational angiography. Advanced morphological and hemodynamic parameters were extracted, with clustering applied to address multicollinearity. Univariate logistic regression identified cluster representatives, and forward selection highlighted the maximum height, Neck inflow rate, and Non-sphericity index as rupture predictors, though only the latter two were significant. Clinical variables like age, sex, and comorbidities were also assessed but failed to predict rupture risk. The full model showed overfitting, with a pseudo-R-2 of 0.142 on the training set but only 0.032 on the test set. A simplified model using just Neck inflow rate and Non-sphericity index performed similarly poorly (pseudo-R-2 of 0.034). Multiple machine learning classifiers were evaluated, with similar performance across models, supporting the model-independence of the results. Overall, neither morphological, hemodynamic, nor clinical variables reliably predicted rupture risk, highlighting the limitations of current methods and underscoring the need for prospective studies and multimodal approaches that integrate imaging biomarkers and compare small and large aneurysms for better risk stratification.

BACKGROUND:The Contour Neurovascular System (Contour) is a novel device designed for the endovascular treatment of wide-necked bifurcation aneurysms (WNBAs). While clinical reports have shown promising results, some cases have failed to achieve satisfactory angiographic outcomes, and the mechanisms driving these differences remain unclear. Detailed hemodynamic analysis is critical to understanding the device's performance and optimizing treatment strategies. METHODS:Based on in vivo medical images of eight patients from eight pre-, eight post-interventional, six first, and six second follow-up examinations, virtual configurations of the Contour placements were established. Based on a complex workflow, the realistic in vivo Contour deformation was virtually simulated. Subsequently, 28 patient-specific hemodynamic simulations were performed, analyzing the intra-aneurysmal blood flow in detail. Neck- and aneurysm-related hemodynamics and morphological changes in Contour and ostium over time were assessed and correlated. RESULTS:The Contour reduced time-averaged intra-aneurysmal velocity (TAv) and wall shear stress (TAWSS) significantly post-intervention in all cases (mean TAv: pre = 0.1 m/s, post = 0.04 m/s; mean TAWSS: pre = 0.57 Pa, post = 0.16 Pa). Long-term follow-up analysis showed a significant reduction when compared to the pre-interventional state. Due to the limitation of missing thrombus modeling, no longitudinal reduction could be derived. Uncovered ostium area was significantly related to TAv and neck inflow rate over time. CONCLUSIONS:In this study the immediate efficacy of the Contour on reducing flow into WNBAs based on in vivo data was demonstrated through numerical analysis. Sufficient ostium coverage by the Contour was found to be important for flow reduction in WNBAs and proper device positioning a key factor for ensuring the long-term efficacy of the Contour.