A5046558394- Advanced MRI Techniques and Applications
- Advanced NMR Techniques and Applications
- Ultrasound and Hyperthermia Applications
- MRI in cancer diagnosis
- Electromagnetic Fields and Biological Effects
- Atomic and Subatomic Physics Research
- Ultrasound Imaging and Elastography
- Microwave Imaging and Scattering Analysis
- Medical Imaging Techniques and Applications
- Functional Brain Connectivity Studies
- Cardiac Imaging and Diagnostics
- Lanthanide and Transition Metal Complexes
- Nuclear Physics and Applications
- NMR spectroscopy and applications
- Electrical and Bioimpedance Tomography
- Electron Spin Resonance Studies
- Eosinophilic Disorders and Syndromes
- Wireless Body Area Networks
- Advanced Neuroimaging Techniques and Applications
- Hearing Loss and Rehabilitation
- Olfactory and Sensory Function Studies
- EEG and Brain-Computer Interfaces
- Cardiac Ischemia and Reperfusion
- Molecular Spectroscopy and Structure
- Phonocardiography and Auscultation Techniques
National Institutes of Health Clinical Center
2024
Center for Devices and Radiological Health
2011-2023
United States Food and Drug Administration
1994-2021
Office of Science
2011-2020
United States Department of Health and Human Services
2015
Schlumberger (United States)
2003
Georgetown University Medical Center
1992-1999
Georgetown University
1989-1999
University of Chicago
1998
Bracco (United States)
1997
A major challenge in cancer biology is to monitor and understand metabolism vivo with the goal of improved diagnosis perhaps therapy. Because complexity biochemical pathways, tracer methods are required for detecting specific enzyme-catalyzed reactions. Stable isotopes such as (13)C or (15)N detection by nuclear magnetic resonance provide necessary information about tissue biochemistry, but crucial metabolites present low concentration therefore beyond threshold traditional methods. solution...
Purpose The test reports for the RF‐induced heating of metallic devices hundreds medical implants have been provided to U.S. Food and Drug Administration as a part premarket submissions. main purpose this study is perform retrospective analysis data in analyze trends correlate them with implant geometric characteristics. Methods ASTM‐based RF from 86 submissions were reviewed by three reviewers. From each report, dimensions values given whole‐body (WB) specific absorption rate (SAR) local...
Purpose: The purpose of this study was to investigate the need for high-resolution detailed anatomical modeling correctly estimate radio-frequency (RF) safety during magnetic resonance imaging (MRI). RF-induced heating near metallic implanted devices depends on electric field tangential device (Etan ). Etan and specific absorption rate (SAR) were analyzed in blood vessels an model understand if a standard gel phantom accurately represents potential tissues due passive vascular implants such...
The aim of this study was to quantify the spatial temperature rises that occur during 1.5- and 3.0-T magnetic resonance imaging (MRI) different types hip arthroplasty implants using metal artifact reduction techniques.Using a prospective in vitro design, we evaluated 4 total constructs clinical techniques including high-bandwidth turbo spin echo (HBW-TSE), slice encoding for correction (SEMAC), compressed sensing SEMAC at 1.5 3.0 T. Each MRI protocol included 6 pulse sequences, with planes,...
To evaluate the efficacy of gadopentetate dimeglumine in MR angiography lower extremities, a flow phantom, seven healthy volunteers, and patients with peripheral vascular disease were studied magnitude contrast (MC) technique. The combination an MC rephase-dephase gradient-refocused-echo pulse sequence, 40-cm-long transmit-receive coil, intravenous administration bolus improved angiographic quality patients. Gadolinium enhancement decreased deleterious saturation effects images popliteal...
It is often difficult for the radiologist to determine if a given sacral meningeal cyst causing symptoms. Radiographic criteria identifying cysts likely be symptomatic are needed. Using conventional magnetic resonance (MR) imaging along with specifically designed flow-sensitive sequence, authors characterized 24 (19 patients) respect diameter and communication subarachnoid space. They found no significant difference in size between asymptomatic (P > .05) but did observe clear-cut disparity...
Superparamagnetic iron oxide nanoparticles (SPIONs, diameters >50 nm) have received great attention due to their promising use as magnetic resonance imaging (MRI) contrast agents. In this study, we evaluated the cellular uptake and biological responses in vitro of ultrasmall SPIONs (USPIONs, < 50 nm). We compared between breast epithelia isolated from healthy cancer donors after exposure carboxy-terminated USPIONs (10 30 nm PEG-coated, 10 non-PEG-coated). The particles were characterized...
Materials with high dielectric constant (HDC) have been used in field MRI to decrease specific absorption rate (SAR), increase magnetic intensity, and signal-to-noise ratio. In previous studies, the HDC materials were placed inside RF coil decreasing space available. This study describes an alternative approach that considers HDC-based sleeve outside coil. The effects of on electromagnetic (EM) studied using numerical simulations a unloaded loaded human head model. addition, experimental EM...
Abstract Mice with subcutaneous RIF‐1 tumors were anesthetized sodium pentobarbital (PB) or ketamine plus acepromazine (KA) before acquisition of in vivo 31 P nuclear magnetic resonance (NMR) spectra from tumors. The area the inorganic phosphate was significantly greater (relative to phosphomonoesters α‐phosphate nucleoside triphosphate) obtained under PB anesthesia, suggesting that hypoxic fraction tumor increased following anesthesia. In near‐infrared laser spectroscopy directly...
Optimal techniques for lung preservation are yet to be defined. Platelet activating factor is a phospholipid released by variety of cells and produces pulmonary abnormalities similar posttransplantation dysfunction. We investigated the strength effect platelet antagonist BN 52021 as compared with that deferoxamine, an iron chelator previously shown improve preservation. Differential function hemodynamics were used assess after 6-hour period cold ischemic storage in modified canine model left...
A novel phantom for image quality testing functional magnetic resonance imaging (fMRI) scans is described.The cylindrical, rotatable, ~4.5L phantom, with eight wedge-shaped compartments, used to simulate rest and activated states. The compartments contain NiCl2 doped agar gel alternating concentrations of (1.4%, 1.6%) produce T1 T2 values approximating brain grey matter. Jacard index was compare the distortions echo planar (EPI) gradient recalled (GRE) scans. Contrast noise ratio (CNR)...
To enhance RF safety when implantable medical devices are located within the body coil but outside imaging region by using a secondary resonator (SR) to reduce electric fields, corresponding specific absorption rate (SAR), and temperature change during MRI.This study was conducted numerical simulations with an American Society for Testing Materials (ASTM) phantom adult human models of Ella Duke from Virtual Family Models, along experimental results obtained ASTM phantom. The circular SR...