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: Cerebrovascular reactivity (CVR) is commonly used to estimate hemodynamic impairment. Conventional use is best-suited to unilateral vascular disease, such that CVR can be normalized to reference values from the contralateral hemisphere or to the posterior circulation territories; however, major confounds have been identified that leave implementation difficult in more common cases of bilateral disease, even despite common cerebellar normalization. Recently, we reported data-driven identification of candidate healthy voxel signatures learned from contemporaneous imaging data. Here, we introduce an entirely inline, automated approach exploiting the dynamics of resting-state blood oxygenation level–dependent (BOLD) functional MR imaging (rs-BOLD) signal from the BOLD baseline, hypothesizing prediction to within 10% error relative to ground truth healthy-voxel CVR values. MATERIALS AND METHODS: Twenty-two subjects with strictly unilateral intracranial steno-occlusive disease (SOD) underwent 28 CVR studies under pharmacologic provocation using acetazolamide with BOLD-MRI (ACZ-BOLD). Separate affected and unaffected hemispheric masks were segmented to train machine learning models to learn signatures of the unaffected hemisphere using the rs-BOLD baseline, as well as anatomic and vascular parameters. Twenty additional healthy subjects from the Human Connectome Project supplemented training, wherein all voxels were classified as normal. Thirty-two distinct time-delays were computed voxel-wise, with 32 maximum correlation values constrained to each of 32 paired arterial territories. Performance in prediction of ground-truth reference CVR was computed and compared. RESULTS: The ensemble model achieved area under the curve of 0.81 in predicting candidate unaffected voxels, demonstrating strong performance in estimation of normal-hemisphere CVR (median absolute percent error 7.28 [95% CI 3.48–10.34] and 5.61 [95% CI 2.90–9.86] to predict median and mean reference CVR, respectively), exhibiting significant improvements over naïve whole-brain voxel selection ( P = .005 and P = .048, respectively) or conventional cerebellar normalization (26.4; 95% CI 10.1–40.3) median and (27.6; 95% CI 23.7–33.2) mean. In 9 bilateral cases assessed to illustrate potential use, the proportion of candidate voxels and corresponding volumes predicted by the ensemble model was significantly lower than in most healthy hemispheres but yielded subjectively improved delineation of putatively abnormal regions. CONCLUSIONS: We demonstrate feasibility of learning unaffected reference voxel CVR signatures for BOLD-CVR MRI. The approach facilitates extension of brain CVR beyond existing constraints in subjects with bilateral disease. ACA : anterior cerebral artery ACZ : acetazolamide AUC : area under the curve BOLD : blood oxygenation level–dependent CVR : cerebrovascular reactivity HCP : Human Connectome Project LightGBM : Light Gradient Boosting Machine max : maximum MLP : multilayer perception rs-BOLD : resting-state BOLD SOD : steno-occlusive disease RFc : Random Forest classifier TS : temporal shift XGBoost : Extreme Gradient Boosting

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AbstractObjective. To evaluate the efficacy of hemodynamic profiling (HDpro)-guided antihypertensive therapy in elderly patients with uncontrolled morning

Background: Intravenous fluid therapy is widely used in emergency departments (EDs) to treat hypovolemia and hypotension. However, its hemodynamic effects are often modest and short-lived. Intravenous fluid therapy requires a peripheral venous catheter, which increases the risk of complications such as catheter failure and phlebitis. Oral fluid therapy represents a simple, noninvasive alternative that has been shown in physiological studies to expand plasma volume and increase blood pressure. No randomized trial has compared oral with intravenous fluid therapy in a general adult ED population. Evidence regarding the feasibility of randomized comparisons of fluid administration modes and whether oral fluid administration can reliably deliver the prescribed volume remains limited. Objective: This #Study aims to evaluate the feasibility of conducting a #RCT #ClinicalTrial of oral vs intravenous fluid therapy in ED patients requiring fluid replacement and to determine whether oral fluid therapy is noninferior to intravenous fluid therapy in achieving the prescribed fluid volume. Methods: This investigator-initiated, multicenter, open-label randomized controlled feasibility and noninferiority trial will enroll 250 adult ED patients prescribed ≥1000 mL of intravenous crystalloid therapy. Participants will be randomized 1:1 to receive either oral fluids or intravenous crystalloid. The primary feasibility outcome is #Protocol adherence, defined as the proportion of randomized participants who receive the allocated route of administration without a major #Protocol deviation. The primary clinical outcome is the proportion of patients achieving the prescribed fluid volume during the ED stay, censored at 48 hours after randomization and analyzed using a noninferiority framework. Noninferiority of oral fluid therapy will be tested against the null hypothesis that the intravenous proportion exceeds the oral proportion by at least the noninferiority margin of 15 percentage points, using the difference in proportions with a 1-sided 97.5% CI (equivalent to a 2-sided 95% CI) from an exact proportion test. The sample size of 250 will provide 90% power at a 1-sided α of .025 under an assumed proportion of 85% in both arms. Results: The #Study was funded by the Region of Southern Denmark in May 2024. Recruitment began in October 2025 at 3 Danish EDs, and 85 participants have been recruited as of September 2026. Recruitment is projected to close in October 2026, with final 30-day follow-up projected for November 2026. No amendments to the #Protocol have been made. Results are expected to be published in summer 2027. Conclusions: This trial will evaluate whether a randomized trial comparing intravenous and oral fluid therapy is feasible in ED patients and whether oral fluid therapy can achieve prescribed fluid volumes comparable to those achieved with intravenous therapy. The findings will inform the design of a future definitive effectiveness trial. Trial Registration: ClinicalTrials.gov NCT07361952; https://clinicaltrials.gov/#Study/NCT07361952