BACKGROUND AND PURPOSE: There is no consensus regarding the optimal imaging technique for assessing aneurysms treated with flow diverters (FDs). The goal was to evaluate the image quality of IV-VasoCT in the follow-up of aneurysms treated with FDs and to explore its potential for depicting braid stent deformation and vessel lumen modifications. MATERIALS AND METHODS: We retrospectively enrolled patients who underwent FD placement for the treatment of aneurysms, with posttreatment IV-VasoCT at 1–3 months and DSA by at least 6 months. IV-VasoCT image quality assessment evaluated vessel opacification, vessel border, stent radiopacity, stent/vessel contrast, and movement artifacts. Braid stent and parent vessel findings were compared between IV-VasoCT and DSA in terms of neointimal lining, stent foreshortening, fish-mouthing, bumping, and braid collapse. RESULTS: Twenty-six aneurysms were evaluated in 24 patients (woman/man: 15/9), with a median age of 54.5 years (interquartile range: 47.0–59.0 years). The in-consensus image quality reading evaluated: vessel opacification as optimal in 19 cases (73.1%); vessel borders as well-defined in 17 (65.4%); stent radiopacity as well-defined in 25 (96.2%); and stent/vessel contrast as optimal in 20 (76.9%). Compared with DSA, IV-VasoCT diagnosed 2 of 3 (66%) cases of neointimal lining, 2 of 2 (100%) cases of fish-mouth, 1 of 2 (50%) cases of foreshortening, 3 of 6 (50%) cases of bumping, and 2 of 2 (100%) cases of braid collapse. CONCLUSIONS: IV-VasoCT is feasible for the noninvasive follow-up of aneurysms treated with FDs. It may depict modifications in braid stent and vessel neointimal lining, but the presence of coils may reduce its image quality because of artifacts. CBCT : conebeam CT DAPT : dual antiplatelet therapy FD : flow diverter fps : frame per second IA-VasoCT : intra-arterial VasoCT IQR : interquartile range IV-VasoCT : intra-venous VasoCT SAPT : single antiplatelet therapy

BACKGROUND AND PURPOSE: The safety and efficacy of intravenous tenecteplase in patients with acute ischemic stroke (AIS) with primary medium and distal vessel occlusions (MDVO) selected for mechanical thrombectomy remain an area of active investigation. This observational study aimed to compare tenecteplase and alteplase in patients with MDVO treated with mechanical thrombectomy (MT). MATERIALS AND METHODS: This was a retrospective, propensity score–weighted analysis of 2 cohorts: patients with primary MDVO who received bridging intravenous thrombolysis before MT, from the multicenter TETRIS registry treated with tenecteplase, and patients from a tertiary center cohort treated with alteplase. The primary outcome was an mRS score of 0–2 at 90 days. Secondary outcomes included mortality, symptomatic intracranial hemorrhage (sICH), and early and final successful reperfusion rates, assessed using the extended TICI (eTICI) 2b–3 scale. RESULTS: We included 110 patients, 65 receiving tenecteplase and 45 receiving alteplase. mRS 0–2 at 90 days was achieved in 53.8% of tenecteplase-treated patients versus 48.9% of alteplase-treated patients ( P = .41). Mortality and sICH rates were similar between groups (12.3% versus 13.3%, P = .68; 3.1% versus 0%, P = .51, respectively). There was no significant difference in early reperfusion between tenecteplase and alteplase (40.2% versus 31.1%; P = .53). Final successful reperfusion did not significantly differ (80.4% versus 88.9%; P = .28). CONCLUSIONS: In MDVO, tenecteplase yielded comparable safety and functional outcomes to alteplase, without statistically significant differences in early or final reperfusion. In light of recent trials questioning the benefit of MT in MDVO, these data suggest comparable safety and functional outcomes between tenecteplase and alteplase as bridging thrombolysis before mechanical thrombectomy, within the limits of this observational study. AcT : Alteplase Compared to Tenecteplase AIS : acute ischemic stroke ESS : effective sample size eTICI : extended TICI EVT : endovascular therapy ICH : intracerebral hemorrhage IVT : intravenous thrombolysis LVO : large vessel occlusion MDVO : medium and distal vessel occlusions MT : mechanical thrombectomy PSOW : propensity score overlap weighting sICH : symptomatic intracranial hemorrhage SITS-MOST : Safe Implementation of Thrombolysis in Stroke–Monitoring Study SMD : standardized mean difference TETRIS : Tenecteplase Treatment in Ischemic Stroke TOPMOST : Treatment for Primary Distal, Medium Vessel Occlusion Stroke

BACKGROUND AND PURPOSE: Sacral dural tears are an underrecognized cause of spontaneous intracranial hypotension, and their clinical behavior and response to treatment remain incompletely defined. We hypothesized that outcomes following epidural patching in sacral dural tears are driven primarily by disease chronicity and baseline imaging features, mirroring patterns observed in other spontaneous intracranial hypotension (SIH) leak subtypes, and are less dependent on procedural variables. MATERIALS AND METHODS: We performed a multicenter retrospective cohort study of patients with SIH attributed to sacral dural tears who underwent epidural patching and had clinical and/or imaging follow-up. Of 61 identified patients, 54 met inclusion criteria. Clinical outcomes, brain and spine imaging findings, and procedural variables were analyzed. Univariate and multivariable logistic regression models were used to identify predictors of clinical and imaging outcomes. Myelographic techniques were compared for rates of precise leak localization. RESULTS: The mean age was 37.8 years, and 85% of patients were women. Complete clinical improvement after patching occurred in 28 of 50 patients (56%), and complete resolution of sacral extradural CSF on follow-up spine MRI occurred in 17 of 37 patients (46%). Greater improvement in Bern score was independently associated with complete clinical improvement (OR 0.73; 95% CI, 0.54–0.99; P = .04) and showed a pattern toward imaging resolution. Unorganized baseline extradural CSF morphology predicted better clinical ( P = .03) and imaging ( P = .03) outcomes. Procedural variables, including injectate type, volume, and needle approach, were not associated with outcome. Dynamic CT myelography precisely localized the leak more frequently than digital subtraction myelography (75% vs 31%; P = .02). Eight patients underwent surgery, with mixed clinical and imaging outcomes. CONCLUSIONS: Epidural patching outcomes in sacral dural tears causing SIH are driven primarily by baseline imaging phenotype, disease stage, and intracranial imaging response rather than procedural technique. These findings support a morphology- and chronicity-aware approach to diagnosis and treatment and suggest that sacral dural tears represent a distinct SIH subtype with outcome patterns similar to other leak mechanisms. AUROC : area under the receiver operating characteristic curve dCTM : dynamic CT myelography DSM : digital subtraction myelography EBP : epidural blood patch IQR : interquartile range RIH : rebound intracranial hypertension SIH : spontaneous intracranial hypotension SLEC : spinal longitudinal extradural collection

SUMMARY: This study aims to characterize the natural history and diagnostic variability of unequivocal intracranial infundibula and diagnostically uncertain outpouchings labeled “aneurysm versus infundibulum”. We retrospectively analyzed 665 intracranial outpouchings detected on CTA, MRA, or DSA at a single-center (2013–2018). Radiology reports classified lesions as unequivocal infundibula ( n =321) or as conundrums with an explicit label of “aneurysm versus infundibulum” ( n =344). Follow-up imaging through December 2023 was reviewed for growth, rupture, or aneurysmal transformation. Ten conundrums with later DSA follow-up also underwent blinded image re-review. A logistic model tested clinical and radiographic predictors of diagnostic ambiguity, and a literature review contextualized anatomic prevalence. Of 321 unequivocal infundibula, 146 (45%) had follow-up imaging. Among 344 conundrums, 208 (61%) were followed, yielding 1040 lesion-years of surveillance across both cohorts. No complications or morphologic changes were observed in either group. Median follow-up among followed infundibula and conundrums was 2.26 (interquartile range [IQR] 0.32–5.34) and 2.31 (IQR 0.20–5.43) years, respectively. Conundrums were more likely than unequivocal infundibula to undergo follow-up imaging ( P < .001). Nonposterior communicating artery location (OR 7.4; 95% CI, 5.11–10.63) and presence of comorbid aneurysms (OR 1.9; 95% CI, 1.15–2.96) independently predicted a conundrum label. Surveillance declined steeply after 5 years, with only 13.4% of infundibula and 17.2% of conundrums still imaged at that horizon. Secondary reassessment of 10 conundrums revealed 100% concordance with DSA when morphologic criteria were rigorously applied. Literature review reaffirmed the predominance of infundibula at the posterior communicating artery but highlighted inconsistent terminology and sparse long-term outcome data. In the largest single-center cohort to date, both classic infundibula and radiologically ambiguous conundrums remained stable over medium-term follow-up. Diagnostic uncertainty appears to stem mainly from interpretive variability rather than true biologic risk. Structured reporting combined with location-informed heuristics could reduce unnecessary surveillance. Acomm : anterior communicating artery CE-MRA : contrast-enhanced MRA IQR : interquartile range OA : outflow angle PCCT : photon-counting CT Pcomm : posterior communicating artery

SUMMARY: The diagnostic yield of CTP for cerebral venous thrombosis (CVT) is uncertain. We aimed to estimate the sensitivity, specificity, predictive values, and area under the curve (AUC) of CTP for CVT diagnosis, hypothesizing that CTP review would increase CVT diagnosis accuracy. This is a retrospective analysis of patients with stroke-like symptoms undergoing brain NCCT, CTA, and CTP at a single center. Patients with a final diagnosis of CVT (8) were analyzed together with a control group (40, 5:1 ratio) by 3 neurologists blinded to the diagnoses. Brain NCCT+/-CTA showed poor sensitivity (37.5%) with high specificity (100%) for CVT diagnosis, which increased to 50% and 100%, respectively, after additional review of all the CTP maps. The discrimination of brain NCCT+/-CTA for CVT was moderate (AUC = 68.8; 95% CI, 50.8–86.7), increasing to AUC = 75 (95% CI, 56.5–93.5) after adding all the CTP maps reviews. AUC : area under the curve CVT : cerebral venous thrombosis DT : delay time

BACKGROUND AND PURPOSE: Venous anatomic variants are common and generally considered normal. However, growing recognition of cerebral venous disorders in neurologic disease has prompted renewed interest in venous architecture, especially with the increasing use of the internal jugular vein (IJV) as a target for outflow augmentation. Establishing baseline data on venous stenosis prevalence in an unselected population is critical for future research. This study aimed to assess the prevalence of IJV stenoses in patients undergoing neck CTA for unrelated indications. MATERIALS AND METHODS: We conducted a multicenter, retrospective study analyzing the venous anatomy of patients who underwent CTA for unrelated conditions, primarily large vessel occlusion. Stenosis was graded on the basis of the percentage of lumen narrowing with a NASCET-style methodology, and the relationship between IJV stenosis severity and suboccipital collateral drainage was evaluated. Consecutive CTAs of patients were queried to map anatomic features. RESULTS: Sixty-eight percent of the 679 total patients had some degree of IJV stenosis. Severe unilateral stenosis (≥51%) was present in approximately 21% of patients, whereas complete or near-complete occlusion was uncommon at 8%. Bilateral high-grade stenosis was noted in 18% of patients with >50% stenosis and in only 2% of patients with >75% stenosis. A greater degree of stenosis correlated with increased suboccipital collateral vein diameter ( P = .0025). CONCLUSIONS: IJV stenosis is common on CTA performed for non-venous indications with a correlation between the degree of stenosis and the suboccipital collateral vein diameter. The clinical significance of these findings and its possible contribution to cerebral venous disorders require further prospective investigation. CVD : cerebral venous outflow disorder IJV : internal jugular vein

BACKGROUND AND PURPOSE: Carotid webs (CWs) are shelf-like fibrous intimal projections in the carotid bulb that perturb laminar flow, promote local stasis, and predispose to embolic stroke. While morphology correlates with events, in vivo hemodynamic markers of stasis are lacking. We hypothesized that multiphase CT angiography can quantify contrast persistence within web recess, and impaired washout may be associated with stroke/transient ischemic attack. MATERIALS AND METHODS: We retrospectively reviewed head and neck CTA performed between January 2021 and June 2024 in adults whose radiology reports mentioned “web.” CWs were confirmed by independent review. Patients were classified as stroke/TIA causing if their ischemic event was attributed to the web, and asymptomatic if the web was incidentally identified or contralateral to the presenting event. Only symptomatic patients and age- and sex-matched asymptomatic patients who underwent multiphase neck CTA were included. ROIs were placed in posterior recess of CWs, proximal and distal arterial lumens. HU were recorded in ROIs on arterial (A) and delayed (D) phases. Aweb and Dweb were defined as web posterior recess HU in both phases; Aref and Dref were defined as the averaged HU from the adjacent proximal and distal arteries. Two indices were derived: contrast-washout ratio (CWR) = (Aweb − Dweb)/(Aref − Dref); contrast-pooling index (CPI) = (Dweb/Dref) − (Aweb/Aref). Continuous variables were compared with t test or Mann-Whitney U test, and categoric variables with Fisher exact tests. RESULTS: Among 190 patients with 206 confirmed webs, we identified 7 symptomatic patients with ischemic stroke/TIA attributed to CW who had neck multiphase CTA and compared with 7 age- and sex-matched asymptomatic patients. Baseline demographics and CW morphology did not differ between cohorts. CWR was lower in symptomatic patients than controls (median [interquartile range (IQR)] 0.672 [0.652–0.920] versus 0.918 [0.819–1.076]; P = .04), indicating reduced washout. CPI was higher in symptomatic patients (median [IQR] 0.098 [0.074–0.212] versus −0.009 [−0.169–0.060]; P = .04), consistent with contrast persistence and blood stasis. CONCLUSIONS: These findings suggest that contrast persistence metrics on multiphase CTA may reflect local stasis within CWs; however, results are preliminary and warrant validation in larger cohorts. ACA : anterior cerebral artery CCA : common carotid artery CPI : contrast-pooling index CWR : contrast-washout ratio CW : carotid web ECST : European Carotid Surgery Trial HU : Hounsfield unit ICC : intraclass correlation coefficient IQR : interquartile range

BACKGROUND AND PURPOSE: The Carotid Plaque Reporting and Data System (Plaque-RADS) score is a comprehensive imaging-based framework for assessing carotid plaque vulnerability. Intraplaque neovascularization (IPN) is closely linked to atherosclerotic plaque progression. However, the interrelationship between Plaque-RADS and IPN and their respective roles in patients with symptomatic carotid stenosis remains incompletely understood. MATERIALS AND METHODS: We retrospectively enrolled 128 patients with unilateral carotid artery stenosis who underwent carotid MR vessel wall imaging and contrast-enhanced ultrasound for integrated plaque characterization. Logistic regression was used to construct predictive models. Model performance was evaluated via the area under the receiver operating characteristic curve (AUC) with DeLong test for comparisons; the Net Reclassification Improvement (NRI) and Integrated Discrimination Improvement (IDI) were calculated to assess incremental predictive value. RESULTS: Patients with symptomatic stenosis had significantly higher Plaque-RADS scores ( P = .001), IPN grades ( P = .002), and plaque volumes ( P = .011) than those with remote symptomatic stenosis or asymptomatic stenosis. Both the Plaque-RADS score and IPN grade showed significant inverse correlations with duration since symptom onset (Plaque-RADS: ρ = –0.296, P = .003; IPN: ρ = –0.282, P = .001). We constructed 5 predictive models: 3 single-indicator models (Plaque-RADS only, IPN only, and plaque volume only), a combined model (Plaque-RADS and IPN), and a comprehensive model incorporating Plaque-RADS, IPN, and plaque volume. The combined model achieved an AUC of 0.751 (95% CI, 0.661–0.841), significantly outperforming single-indicator models (plaque volume: 0.644, P = .021; Plaque-RADS only: 0.684, P = .042; IPN only: 0.688, P = .038) but comparable with the comprehensive model (0.770; P = .247). The NRI and IDI of the combined model showed significant incremental value over single-indicator models (all. P < .05) but no significant improvement compared with the comprehensive model (both P = .218). CONCLUSIONS: Plaque-RADS and the IPN grade are independent and complementary imaging biomarkers for identifying recent cerebrovascular events. AUC : area under the receiver operating characteristic curve CEUS : contrast-enhanced ultrasound IDI : Integrated Discrimination Improvement IPH : intraplaque hemorrhage IPN : intraplaque neovascularization max : maximum MR-VWI : MR vessel wall imaging NRI : Net Reclassification Improvement NWI : normalized wall index RADS : Reporting and Data System SNAP : Simultaneous Non-contrast Angiography and intraPlaque hemorrhage VISTA : volume isotropic turbo spin-echo acquisition