A5063771288- Advanced Neuroimaging Techniques and Applications
- Advanced MRI Techniques and Applications
- Fetal and Pediatric Neurological Disorders
- Functional Brain Connectivity Studies
- MRI in cancer diagnosis
- Medical Imaging Techniques and Applications
- Bipolar Disorder and Treatment
- Cerebrospinal fluid and hydrocephalus
- Bone and Joint Diseases
- Pituitary Gland Disorders and Treatments
- Origins and Evolution of Life
- Genetics and Neurodevelopmental Disorders
- Spinal Dysraphism and Malformations
- Micro and Nano Robotics
- Traumatic Brain Injury Research
- HIV Research and Treatment
- Epilepsy research and treatment
- Cerebral Palsy and Movement Disorders
- Chemical Reactions and Isotopes
- Microfluidic and Bio-sensing Technologies
- Genetic Associations and Epidemiology
- Atomic and Subatomic Physics Research
- Meningioma and schwannoma management
- RNA regulation and disease
- Genomic variations and chromosomal abnormalities
National Institute of Neurological Disorders and Stroke
2014-2023
National Institutes of Health
2014-2023
National Institute of Mental Health
2022-2023
Oxford University Press (United Kingdom)
2020
Uniformed Services University of the Health Sciences
2011
Center for Neuroscience and Regenerative Medicine
2011
Eunice Kennedy Shriver National Institute of Child Health and Human Development
2007-2010
University of Arizona
2000-2005
University of Cambridge
2001
The goal of this study was to better understand the changes in tissue microstructure that underlie white matter diffusion ALS patients.Diffusion tensor imaging carried out postmortem brains 4 patients and two subjects without neurological disease on a 7 T MRI scanner using steady-state free precession sequences. Fractional anisotropy (FA) measured genu, body, splenium corpus callosum formalin-fixed hemispheres. FA body genu expressed as ratio splenium, region unaffected ALS. After imaging,...
Neural tissue microstructure plays an important role in developmental, physiological and pathophysiological processes. Diffusion tensor distribution (DTD) MRI helps probe subvoxel heterogeneity by describing water diffusion within a voxel using ensemble of non-exchanging compartments characterized probability density function tensors. In this study, we provide new framework for acquiring multiple encoding (MDE) images estimating DTD from them the human brain vivo. We interfused pulsed field...
Purpose To demonstrate that the temporal signal‐to‐noise ratio (SNR) of generalized autocalibrating partially parallel acquisitions (GRAPPA) accelerated echo planar imaging (EPI) can be enhanced and made more spatially uniform by using a fast low angle shot (FLASH) based calibration scan. Methods EPI phantom human brains were acquired at 3 Tesla without with GRAPPA acceleration factor 2. The data reconstructed scans FLASH acquisition schemes. increase in signal fluctuation due to...
Abstract Previous work using transcranial magnetic stimulation (TMS) demonstrated that the right presupplementary motor area (preSMA), a node in fronto‐basal‐ganglia network, is critical for response inhibition. However, TMS influences interconnected regions, raising possibility of link between preSMA activity and functional connectivity within network. To understand this relationship, we applied single‐pulse to during resonance imaging when subjects were at rest examine changes neural...
To propose a methodology for assessment of algorithms that correct distortions due to motion, eddy-currents, and echo planar imaging in diffusion weighted images (DWIs).The proposed method evaluates correction performance by measuring variability across datasets the same object acquired with having different directions, thereby overcoming unavailability ground-truth, undistorted DWIs. A comprehensive MRI dataset, collected using suitable experimental design, is made available scientific...
Abstract Objectives Bipolar disorder (BD) and familial risk for BD have been associated with aberrant white matter (WM) microstructure in the corpus callosum fronto‐limbic pathways. These abnormalities might constitute trait or state marker suggested to result from maturation relate difficulties emotion regulation. Methods To determine whether WM alterations represent a trait, disease resilience marker, we compared youth at (n = 36 first‐degree relatives, REL) 36) healthy volunteers 36, HV)...
Abstract This work presents a basic framework for constructing 3D analytical MRI phantom in the Fourier domain. In image domain is modeled after of Kak and Roberts on version famous Shepp‐Logan head phantom. consists several ellipsoids different sizes, orientations, locations, signal intensities (or gray levels). It will be shown that k ‐space derived from can analytically expressed. As consequence, it enables one to bypass need interpolation when testing image‐reconstruction algorithms....
Background There are currently no widely accepted neuro-HIV small animal models. We wanted to validate the HIV-1 Transgenic rat (Tg) as an appropriate model and then establish in vivo imaging biomarkers of neuropathology, within this model, using MR structural diffusion tensor (DTI). Methods Young middle-aged Tg control rats were imaged MRI. A subset animals underwent longitudinal repeat six months later. Total brain volume (TBV), ventricular (VV) parenchymal (PV = TBV–VV) measured....
T1 relaxation and water mobility generate eloquent MRI tissue contrasts with great diagnostic value in many neuroradiological applications. However, conventional methods do not adequately quantify the microscopic heterogeneity of these important biophysical properties within a voxel, therefore have limited biological specificity. We describe new correlation spectroscopic (CS) method for measuring how mean diffusivity (MD) co-vary environments. develop clinical pulse sequence that combines...
Supercoiling motions that accompany the growth of bacterial macrofibers (multicellular filamentous structures formed in B. subtilis by cell division without separation) are responsible for rolling, pivoting, and walking fibers on a surface. Fibers possess fulcrum about which they pivot step chiral manner; forces torques associated with growth, when blocked friction, result self-propulsion. The elastic engine drives macrofiber generates estimated as $\ensuremath{\mu}\mathrm{dyn}\mathrm{cm}$...
Many brain imaging studies have demonstrated reductions in gray and white matter volumes alcoholism, with fewer investigators using diffusion tensor (DTI) to examine the integrity of pathways. Among various medical conditions, alcoholism post-traumatic stress disorder (PTSD) are two comorbid diseases that similar degenerative effects on integrity. Therefore, understanding differentiating these would be very important characterizing PTSD. Alcoholics known neurocognitive deficits...
Abstract Single‐shot echo‐planar imaging is the most common acquisition technique for whole‐brain diffusion tensor (DTI) studies in vivo. Higher field MRI systems are readily available and advantageous acquiring DTI due to increased signal. One of practical issues with single‐shot at high‐field incomplete fat suppression resulting a chemically shifted artifact within brain image. Unsuppressed especially detrimental because coefficient two orders magnitude lower than that parenchyma,...
Purpose We propose a new generalized diffusion tensor imaging (GDTI) experimental design and analysis framework for efficiently measuring orientationally averaged diffusion‐weighted images (DWIs), which remove bulk signal modulations attributed to anisotropy quantify isotropic higher‐order tensors (HOT). illustrate how this accelerates the clinical measurement of rotation‐invariant tissue microstructural parameters derived from HOT, such as HOT‐Trace mean t‐kurtosis. Theory Methods For large...
Abstract Interictal epileptiform discharges have been shown to propagate from focal epileptogenic sources as travelling waves or through more rapid white matter conduction. We hypothesize that both modes of propagation are necessary explain interictal discharge timing delays. propose a method that, for the first time, incorporates identify unique potential activity. retrospectively analysed 38 epilepsy patients who underwent intracranial EEG recordings and diffusion-weighted imaging surgery...
There is a need for an imaging sequence that can provide high-resolution diffusion tensor images at 3T near air-tissue interfaces. By employing radial fast spin-echo (FSE) collection in conjunction with magnitude filtered back-projection reconstruction, diffusion-weighted be produced without susceptibility artifacts. However, violation of the Carr-Purcell-Meiboom-Gill (CPMG) condition prepared magnetization prominent problem FSE trains magnified higher fields. The unique aspect violating...