A5051620273- Acute Ischemic Stroke Management
- Intracranial Aneurysms: Treatment and Complications
- Cerebrovascular and Carotid Artery Diseases
- Vascular Malformations Diagnosis and Treatment
- Traumatic Brain Injury and Neurovascular Disturbances
- Venous Thromboembolism Diagnosis and Management
- Moyamoya disease diagnosis and treatment
- Advanced MRI Techniques and Applications
- Intracerebral and Subarachnoid Hemorrhage Research
- MRI in cancer diagnosis
- Stroke Rehabilitation and Recovery
- Cerebrospinal fluid and hydrocephalus
- Meningioma and schwannoma management
- Advanced Neuroimaging Techniques and Applications
- Cerebral Venous Sinus Thrombosis
- Neurosurgical Procedures and Complications
- Neurological Complications and Syndromes
- Vascular Anomalies and Treatments
- Cardiac Imaging and Diagnostics
- Radiomics and Machine Learning in Medical Imaging
- Spinal Fractures and Fixation Techniques
- Vascular Malformations and Hemangiomas
- Peripheral Artery Disease Management
- Intraoperative Neuromonitoring and Anesthetic Effects
- Trigeminal Neuralgia and Treatments
Stanford Medicine
2013-2024
Stanford University
2014-2024
University of Pittsburgh
1991-2022
University Medical Center Hamburg-Eppendorf
2021-2022
Universität Hamburg
2021-2022
Society of Interventional Radiology
2021
Marks and Spencer (United Kingdom)
1999-2020
Palo Alto University
2000-2020
Stanford Health Care
2000-2019
Cognitive Neuroimaging Lab
2017-2019
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...
The only Food and Drug Administration (FDA)-approved treatment for acute ischemic stroke is tissue plasminogen activator (tPA) given intravenously within 3 hours of symptom onset. An alternative strategy opening intracranial vessels during mechanical embolectomy, especially patients ineligible intravenous tPA.We investigated the safety efficacy a novel embolectomy device (Merci Retriever) to open occluded large 8 onset symptoms in prospective, nonrandomized, multicenter trial. All were tPA....
Abstract Objective To determine whether prespecified baseline magnetic resonance imaging (MRI) profiles can identify stroke patients who have a robust clinical response after early reperfusion when treated 3 to 6 hours symptom onset. Methods We conducted prospective, multicenter study of 74 consecutive admitted academic centers in North America and Europe. An MRI scan was obtained immediately before treatment with intravenous tissue plasminogen activator Baseline were used categorize into...
Abstract Diffusion‐weighted imaging (DWI) detects small changes in water diffusion that occur ischemic brain. This study evaluated the clinical usefulness of a phase‐navigated spin‐echo DWI sequence compared with T2‐weighted magnetic resonance (T2W MRI) patients cerebral ischemia and assessed apparent coefficient (ADC) (T2WI) over time. ADC values T2 ratios image intensity were measured from region corresponding contralateral brain region. The histories scans obtained course 1 year reviewed...
<b>Background: </b> Diffusion-weighted (DWI) and perfusion-weighted (PWI) MRI are powerful new techniques for the assessment of acute cerebral ischemia. However, quantitative data comparing severity clinical neurologic deficit with results DWI or PWI in earliest phases stroke scarce. Such information is vital if potentially to be used as an objective adjunctive measure outcome. <b>Objective: The authors compared initial lesion volumes subsequent 24-hour determined by National Institutes...
Object No definitive treatment exists to restore lost brain function following a stroke. Transplantation of cultured neuronal cells has been shown be safe and effective in animal models stroke Phase 1 human trial. In the present study authors tested usefulness neuron transplantation followed by participation 2-month rehabilitation program compared with alone patients substantial fixed motor deficits associated basal ganglia Methods Human (LBS-Neurons; Layton BioScience, Inc.) were delivered...
Object Moyamoya disease (MMD) is a rare cerebrovascular mainly described in the Asian literature. To address lack of data on clinical characteristics and long-term outcomes treatment MMD North America, authors analyzed their experience at Stanford University Medical Center. They report consecutive series patients treated for detail demographics, characteristics, surgical outcomes. Methods Data obtained 329 with microsurgically by senior author (G.K.S.) between 1991 2008 were analyzed....
A prospective longitudinal diffusion-weighted and perfusion-weighted magnetic resonance imaging (DWI/PWI) study of stroke patients (n = 21) at five distinct time points was performed to evaluate lesion evolution assess whether DWI PWI can accurately objectively demonstrate the degree ischemia-induced deficits within hours after onset. Patients were scanned first 7 symptom onset then subsequently 3 6 hours, 24 36 5 days, 30 days initial scan. Lesion dynamic during month stroke. Most (18 19,...
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...
After the occlusion of an internal carotid artery principal source collateral flow is through arteries circle Willis, but size and patency these are quite variable. Study anatomy pathways in patients with internal-carotid-artery or without infarction watershed area deep white matter may identify patterns that afford protection from ischemic infarction.Using conventional magnetic resonance imaging three-dimensional phase-contrast angiography, we evaluated 29 consecutive (32 hemispheres at...
The authors describe a technique for obtaining angiographic images by means of spiral computed tomography (CT), preprocessing reconstructed three-dimensional sections to suppress bone, and maximum intensity projection. has some limitations, but preliminary results in 48 patients have shown excellent anatomic correlation with conventional angiography studies the abdomen, circle Willis brain, extracranial carotid arteries. With continued development evaluation, CT may prove useful as screening...
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...
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).
<h3>Importance</h3> Predicting infarct size and location is important for decision-making prognosis in patients with acute stroke. <h3>Objectives</h3> To determine whether a deep learning model can predict final lesions using magnetic resonance images (MRIs) acquired at initial presentation (baseline) to compare the current clinical prediction methods. <h3>Design, Setting, Participants</h3> In this multicenter prognostic study, specific type of neural network image segmentation (U-net) was...
Heavy-charged-particle radiation has several advantages over protons and photons for the treatment of intracranial lesions; it an improved physical distribution dose deep in tissue, a small angle lateral scattering, sharp distal falloff dose.
The authors evaluated a phase-navigated spin-echo (SE) motion-correction sequence for use at diffusion-weighted (DW) magnetic resonance (MR) imaging after cerebral infarction.Twenty-nine patients underwent 32 conventional T2-weighted fast SE and DW stroke (n=25), transient ischemic attack (n=3), or reversible neurologic deficit (n=1). Imaging was performed in standard head holder with padding. Apparent diffusion coefficient (ADC) maps were constructed.DW images depicted high signal intensity...
The most serious and frequent complication of intracranial arteriovenous malformations (AVMs) is hemorrhage. Identification patients at greatest risk for bleeding would be beneficial. Detailed analysis vascular architecture was performed in 65 with AVMs to identify the characteristics that correlated Fifteen were assessed. Hemorrhage present 45 (69%). following positively hemorrhage (Fisher-Irwin exact test): central venous drainage (P less than .0001), periventricular or intraventricular...
To compare diffusion-weighted MRI (DWI) and CT with respect to accuracy of localizing acute cerebral infarction; sensitivity, specificity, interrater reliability for identifying more than one-third middle artery (MCA) territory involvement; correlation lesion volume final infarct volume.Nineteen consecutive stroke patients underwent DWI within 7 hours onset a follow-up examination 36 after symptom onset, which served as the "gold standard" location extent MCA involvement. Each scan was...
PURPOSE: To report initial clinical experience with stent placement in the cerebrovascular circulation. MATERIALS AND METHODS: Four patients underwent arterial or venous placement. Two had cervical internal carotid artery dissections, aneurysms and stenoses of distal artery. occlusive disease involving major dural sinuses, substantial pressure gradients across stenoses. RESULTS: Immediately after placement, true lumina returned to normal diameter both were more than 90% occluded. Follow-up...
Background and Purpose —The heterogeneity of stroke makes outcome prediction difficult. Neuroimaging parameters may improve the predictive value clinical measures such as National Institutes Health Stroke Scale (NIHSS). We investigated whether volume early ischemic brain lesions assessed with diffusion-weighted imaging (DWI) was an independent predictor functional outcome. Methods —We retrospectively selected patients nonlacunar in anterior circulation from 4 prospective Stanford Center...
Background and Purpose— Medical treatment of symptomatic intracranial stenosis carries a high risk stroke. This study was done to evaluate the clinical angiographic outcomes after angioplasty for this disease. Methods— A total 120 patients with 124 stenoses were treated by primary angioplasty. All had neurologic symptoms (stroke or transient ischemic attack) attributable ≥50%. Angiograms evaluated before degree stenosis. Results— Pretreatment varied from 50% 95% (mean 82.2±10.2)....
Determining the presence and adequacy of collateral blood flow is important in cerebrovascular disease. Therefore, we explored whether a noninvasive imaging modality, arterial spin labeling (ASL) MRI, could be used to detect intensity using digital subtraction angiography (DSA) stable xenon CT cerebral as gold standards for collaterals flow, respectively.ASL DSA were obtained within 4 days each other 18 patients with Moyamoya Two neurointerventionalists scored images grading scale regions...