A5014950010- Acute Ischemic Stroke Management
- Cerebrovascular and Carotid Artery Diseases
- Traumatic Brain Injury and Neurovascular Disturbances
- Venous Thromboembolism Diagnosis and Management
- Stroke Rehabilitation and Recovery
- Advanced MRI Techniques and Applications
- MRI in cancer diagnosis
- Cardiac Imaging and Diagnostics
- Advanced Neuroimaging Techniques and Applications
- Intracerebral and Subarachnoid Hemorrhage Research
- Cardiac Arrest and Resuscitation
- Peripheral Artery Disease Management
- Traumatic Brain Injury Research
- Radiomics and Machine Learning in Medical Imaging
- Neurological Disease Mechanisms and Treatments
- Medical Imaging and Analysis
- S100 Proteins and Annexins
- Neuroinflammation and Neurodegeneration Mechanisms
- Advanced X-ray and CT Imaging
- Intracranial Aneurysms: Treatment and Complications
- Photoacoustic and Ultrasonic Imaging
- Clinical practice guidelines implementation
- Bone and Joint Diseases
- Neurosurgical Procedures and Complications
- Cerebrospinal fluid and hydrocephalus
Stanford University
2016-2025
Stanford Medicine
2016-2025
Inserm
2013-2024
Institut de Psychiatrie et Neurosciences de Paris
2023-2024
Université Toulouse III - Paul Sabatier
2023
Fondation de Rothschild
2021-2023
Palo Alto University
2013-2023
Universität Hamburg
2021-2022
University Medical Center Hamburg-Eppendorf
2021-2022
John Wiley & Sons (United States)
2021
Thrombectomy is currently recommended for eligible patients with stroke who are treated within 6 hours after the onset of symptoms.We conducted a multicenter, randomized, open-label trial, blinded outcome assessment, thrombectomy in to 16 they were last known be well and had remaining ischemic brain tissue that was not yet infarcted. Patients proximal middle-cerebral-artery or internal-carotid-artery occlusion, an initial infarct size less than 70 ml, ratio volume on perfusion imaging 1.8...
We sought to assess whether the volume of ischemic penumbra can be estimated more accurately by altering threshold selected for defining perfusion-weighting imaging (PWI) lesions.DEFUSE is a multicenter study in which consecutive acute stroke patients were treated with intravenous tissue-type plasminogen activator 3 6 hours after onset. Magnetic resonance scans obtained before, after, and 30 days treatment. Baseline posttreatment PWI volumes defined according increasing Tmax delay thresholds...
Rationale Early reperfusion in patients experiencing acute ischemic stroke is effective with large vessel occlusion. No randomized data are available regarding the safety and efficacy of endovascular therapy beyond 6 h from symptom onset. Aim The aim study to demonstrate that, among anterior circulation occlusion who have a favorable imaging profile on computed tomography perfusion or magnetic resonance imaging, Food Drug Administration 510 K-cleared mechanical thrombectomy device reduces...
Background and Purpose— The aim of this study was to determine if automated MRI analysis software (RAPID) can be used identify patients with stroke in whom reperfusion is associated an increased chance good outcome. Methods— Baseline diffusion- perfusion-weighted scans from the Diffusion Perfusion Imaging Evaluation for Understanding Stroke Evolution (DEFUSE; n=74) Echoplanar Thrombolytic Trial (EPITHET; n=100) were reprocessed RAPID. Based on RAPID-generated diffusion-weighted imaging...
We evaluate associations between the severity of magnetic resonance perfusion-weighted imaging abnormalities, as assessed by hypoperfusion intensity ratio (HIR), on infarct progression and functional outcome in Diffusion Perfusion Imaging Evaluation for Understanding Stroke Evolution Study 2 (DEFUSE 2).
Abstract Objective Outcome prediction is challenging in comatose postcardiac arrest survivors. We assessed the feasibility and prognostic utility of brain diffusion‐weighted magnetic resonance imaging (DWI) during first week. Methods Consecutive patients were prospectively enrolled. AWI data who met predefined specific criteria used to determine distinguishing apparent diffusion coefficient (ADC) thresholds. Group 1 death at 6 months absent motor response or pupillary reflexes bilateral...
Background and Purpose— To refine the definition of malignant magnetic resonance imaging profile in acute stroke patients using baseline diffusion-weighted (DWI) perfusion-weighted (PWI) findings from pooled DEFUSE/EPITHET database. Methods— Patients presenting with within 3 to 6 hours symptom onset were treated tissue plasminogen activator or placebo. Baseline follow-up DWI PWI images both studies reprocessed same software program. A receiver operating characteristic curve analysis was used...
knowledge on the natural history and clinical impact of perihematomal edema (PHE) associated with intracerebral hemorrhage is limited. We aimed to define time course, predictors, significance PHE measured by serial magnetic resonance imaging.patients primary supratentorial ≥ 5 cm(3) underwent MRIs at prespecified intervals during first month. Hematoma (H(v)) (E(v)) volumes were fluid-attenuated inversion recovery images. Relative was defined as E(v)/H(v). Neurologic assessments performed...
Diffusion-weighted imaging (DWI) is commonly used to assess irreversibly infarcted tissue but its accuracy challenged by reports of diffusion lesion reversal (DLR). We investigated the frequency and implications for mismatch classification DLR using from EPITHET (Echoplanar Imaging Thrombolytic Evaluation Trial) DEFUSE (Diffusion Perfusion Understanding Stroke Evolution) studies. In 119 patients (83 treated with IV plasminogen activator), follow-up images were coregistered acute lesions...
Background MRI-based selection of patients for acute stroke interventions requires rapid accurate estimation the infarct core on diffusion-weighted MRI. Typically used manual methods to delineate restricted diffusion lesions are subjective and time consuming. These limitations would be overcome by a fully automated method that can rapidly objectively ischemic core. An require predefined criteria identify Aim The aim this study is determine apparent coefficient-based implemented in software...
Differences in research methodology have hampered the optimization of Computer Tomography Perfusion (CTP) for identification ischemic core. We aim to optimize CTP core using a novel benchmarking tool. The tool consists an imaging library and statistical analysis algorithm evaluate performance CTP. was used in-house developed CTP-software algorithm. Imaging data 103 acute stroke patients were included Median time from onset CT 185 min (IQR 180-238), median between completion start MRI 36...
Agreement between physicians to define the likelihood of a transient ischemic attack (TIA) remains poor. Several studies have compared neurologists with nonneurologists, and among themselves, but not fellowship-trained stroke neurologists. We investigated diagnostic agreement in 55 patients suspected TIA.The history physical examination findings referred Stanford TIA clinic from emergency room were blindly reviewed by 3 who had no knowledge any test results or patient outcomes. Each...
Diffusion-weighted magnetic resonance imaging of the brain is a promising technique to help predict functional outcome in comatose survivors cardiac arrest. We aimed evaluate prospectively temporal-spatial profile apparent diffusion coefficient changes during first 8 days after arrest.Apparent values were measured by 2 independent and blinded investigators predefined regions 18 good- 15 poor-outcome patients with 38 scans compared those 14 normal controls. The same also assessed...
Background The degree of variability in the rate early diffusion-weighted imaging expansion acute stroke has not been well characterized. Aim We hypothesized that patients with slowly expanding lesions would have more penumbral salvage and better clinical outcomes following endovascular reperfusion than rapidly lesions. Methods In first part this substudy DEFUSE 2, growth curves were constructed for >90% <10% reperfusion. Next, initial was determined all a clearly established time...
Background and Purpose— Our aim was to determine the relationships between angiographic collaterals diffusion/perfusion findings, subsequent infarct growth, clinical outcome in patients undergoing endovascular therapy for ischemic stroke. Methods— Sixty with a thrombolysis cerebral infarction (TICI) score of 0 or 1 internal carotid artery/M1 occlusion at baseline were evaluated. A blinded reader assigned collateral using previous 5-point scale, from (no flow) 4 (complete/rapid entire...
Atrial fibrillation is associated with greater baseline neurological impairment and worse outcomes following ischemic stroke. Previous studies suggest that volumes of more severe hypoperfusion in patients history atrial may explain this association. We further investigated association by comparing without on initial examination stroke using pooled multimodal magnetic resonance imaging clinical data from the Echoplanar Imaging Thrombolytic Evaluation Trial Diffusion Perfusion for...
Objective To assess the utility of computed tomographic (CT) perfusion for selection patients endovascular therapy up to 18 hours after symptom onset. Methods We conducted a multicenter cohort study consecutive acute stroke scheduled undergo within 90 minutes baseline CT perfusion. Patients were classified as “target mismatch” if they had small ischemic core and large penumbra on their Reperfusion was defined >50% reduction in critical hypoperfusion between 36‐hour follow‐up magnetic...
In this study, we compare the performance of pretreatment Alberta Stroke Program Early Computed Tomographic scoring (ASPECTS) using noncontrast CT (NCCT) and MRI in a large endovascular therapy cohort.Prospectively enrolled patients underwent baseline NCCT started within 12 hours stroke onset. Inclusion criteria for analysis were evaluable NCCT, diffusion-weighted (DWI), 90-day modified Rankin Scale scores. Two expert readers graded ischemic change on DWI ASPECTS. ASPECTS scores analyzed...
We hypothesized that automated assessment of collaterals on computed tomography perfusion can predict the rate infarct growth during transfer from a primary to comprehensive stroke center for endovascular treatment. identified consecutive patients (N = 28) and assessed their based hypoperfusion intensity ratio (HIR) prior transfer. Infarct was strongly correlated with HIR (r 0.78, p < 0.001). Receiver operating characteristic analysis ≥ 0.5 as optimal predicting growth. Patients had median...
Background and Purpose— It is hypothesized that early diffusion-weighted imaging (DWI) lesions accurately estimate the size of irreversibly injured core thresholded perfusion-weighted (PWI) (time to maximum tissue residue function [Tmax] >6 seconds) approximate volume critically hypoperfused tissue. With incomplete reperfusion, union baseline DWI posttreatment PWI predict infarct volume. Methods— This a substudy Diffusion Perfusion Imaging Evaluation for Understanding Stroke Evolution...
Background and Purpose- The effect of leptomeningeal collaterals for acute ischemic stroke patients with large vessel occlusion in the late window (>6 hours from last known normal) remains unknown. We sought to determine if collateral status on baseline computed tomography angiography impacted neurological outcome, core growth, moderated endovascular thrombectomy window. Methods- This is a prespecified analysis DEFUSE 3 (Endovascular Therapy Following Imaging Evaluation Ischemic Stroke)....
Background and Purpose— The aim of this study was to assess the frequency extent early diffusion-weighted imaging (DWI) lesion reversal after endovascular therapy determine whether is sustained or transient. Methods— MRI with DWI perfusion performed before (DWI 1) within 12 hours 2) treatment; follow-up obtained on day 5. Both DWIs were coregistered MRI. Early defined as volume 1 that not superimposed 2 lesion. Permanent 5 infarct volume. Associations between clinical outcomes in patients...
To evaluate whether time to treatment modifies the effect of endovascular reperfusion in stroke patients with evidence salvageable tissue on MRI.