1994 — 2002 |
Zhong, Jianhui |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. R29Activity Code Description: Undocumented code - click on the grant title for more information. |
Quantitation of Diffusion Effects in Mr Imaging of Brain
This study aims to better understand the information provided by diffusion weighted magnetic resonance imaging (MRI) in tissues. As extensive uses of diffusion-weighted imaging (DWI) techniques evolve, it is essential to develop a greater understanding of the factors that affect diffusion in tissues. The specific issues we will address are: (l) Quantitative determination of the magnitude and time course of changes in water diffusion coefficient that happen during pathological occurrences such as stroke and seizure, using animal models we have developed. Diffusion- weighted imaging will be obtained with time resolution on order of seconds, and during the acute stages of stroke and seizure; (2) Quantitative evaluation of different mechanisms responsible for the alteration of apparent water diffusion coefficient (ADC), including changes in restriction of water diffusion during pathological changes, cytosolic streaming motion, and variations of local magnetic field gradient due to susceptibility difference caused by oxyhemoglobin/ deoxyhemoglobin conversion. We will use specifically designed experiments in simple phantoms, perfused cells, freshly excised tissues, and animal models to address each of these; (3) Develop a model for water diffusion in heterogeneous systems such as tissues based on a clear understanding and quantitative evaluation of each individual mechanism that affects water diffusion. Our own preliminary observation of reduction in ADC during seizure has highlighted the need to quantitatively validate the hypotheses concerning ADC reduction in ischemia that have been suggested by other researchers. Since ischemia and seizure represent two quite different biological conditions (blood flow, oxygenation, and energy status, etc), close comparison of the two models and quantitative studies of individual mechanisms should facilitate improved understanding of the ADC changes in both. We will use NMR spectroscopic and imaging methods based on relaxation and diffusion measurements to quantify water transport among diffusion barriers and across cell membranes or capillary walls of finite permeability. We will use numerical analysis and computer simulations to quantify diffusion among barriers of different shapes, sizes, and different boundary conditions. We will use the NMR q-space concepts developed by Callaghan (1991) to study microstructure and dynamics beyond the resolution of conventional MRI. The q-space imaging is based on the pulsed gradient spin-echo (PGSE) method first developed by Stejeskal and Tanner (1965), and it can be used to characterize water displacement profiles which reflect, if analyzed appropriately, the autocorrelation function of compartment dimensions as well as the relative number and sizes of differently diffusing compartments. These new methods are potentially very powerful at providing new insights into diffusion in heterogeneous compartmented systems such as tissue, but to date their use has been restricted largely to inanimate samples. We will perform experiments on our 2T and 7T scanners both of which are equipped with high strength, shielded magnetic field gradients. A further significance of this work is that it would evaluate the value of the q-space imaging technique for biological samples.
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2002 — 2005 |
Aslin, Richard [⬀] Newport, Elissa (co-PI) [⬀] Parker, Kevin Bavelier, Daphne (co-PI) [⬀] Zhong, Jianhui |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Acquisition of a Magnetic Resonance Imaging System to Assess Brain Plasticity @ University of Rochester
With support from a National Science Foundation Major Research Instrumentation award, Dr. Richard Aslin and his colleagues at the University of Rochester will establish the Rochester Center for Brain Imaging (RCBI). The overall goal of this new center is to assess the plasticity of the adult and child brain as it adapts to altered and varied experiences. One type of alteration is the loss of sensory input in a single modality (e.g., the loss of vision or hearing because of blindness or deafness). Previous research at Rochester has shown that congenitally deaf individuals who use sign language do so with the same parts of the brain (the left hemisphere) that are usually used for spoken language, despite relying on the visual rather than the auditory modality. Deaf individuals also have greater sensitivity to patterns of movement in the peripheral visual field because they rely more on signed language inputs delivered in the visual modality. These patterns of brain plasticity are the result of altered sensory input during early development and have important implications for the brain's ability to compensate for deprivation and injury, provided that it has time during early development to adapt to these unusual circumstances. Similar mechanisms of plasticity may be present in adults as they learn a new task or compensate for brain injury. The Rochester group will use functional magnetic resonance imaging (fMRI) to study both long-term (developmental) and short-term aspects of brain plasticity in adults, children, and non-human primates. The research will provide important insights into the neural mechanisms of learning and plasticity and the keys to the brain's ability to adapt to novel experiences.
Working with a team of cognitive scientists and neuroscientists, as well as magnetic resonance physicists and image processing engineers, Dr. Aslin will supervise the purchase, installation, and operation of a 3 tesla (T) fMRI system designed to measure the microscopic changes in blood oxygen level that occur in localized regions of the brain as participants perform a variety of tasks. This system, which is state-of-the-art in the field of human brain imaging, will provide a group of over 30 researchers from the University of Rochester and Cornell University (90 miles from Rochester) with the capability to explore a variety of issues in human brain plasticity and recovery of function after natural deprivation, injury, or disease. A key feature of the new center is a team of physicists and engineers who will develop new ways for fMRI to reveal even more fine-grained details about the functioning and visualization of the brain.
This project is important for several reasons. It will provide a first-class facility for non-invasive brain imaging to a group of researchers at Rochester who have already demonstrated their ability to conduct cutting-edge research in cognitive neuroscience. The RCBI will also play a significant role in the training of future scientists by actively involving graduate and undergraduates students from the University of Rochester and Cornell University, as well as undergaduates from the State University of New York at Geneseo (a non-Ph.D.-granting college located 30 miles from Rochester) in state-of-the-art brain imaging research. The new center provides an excellent vehicle to teach the principles of fMRI to a new generation of students who will become leaders in the field of cognitive neuroscience.
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2002 — 2004 |
Zhong, Jianhui |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Biophysical Basis of Brain Idqc Mr Imaging @ University of Rochester
The broad, long-term objective of this application is to develop intermolecular double-quantum coherence (iDQC) MR imaging with particular focus on applications in the brain. This is based on the primary hypothesis that iDQC provides novel and unique imaging contrast which is relevant to and potentially useful in a wide variety of important MRI applications, including brain fMRI, detection of hypoxia in tumors, diffusion-weighted imaging, and characterization of trabecular bones. However, owing to the early nature of the technique, we believe that it is crucial to gain a better understanding of fundamentals of iDQC imaging contrast mechanisms, and to determine the key factors for imaging optimization before applications of iDQC imaging become practical. The specific aims of this proposal are therefore to quantify the novel iDQC image contrast in terms of intrinsic parameters (including relaxation, diffusion, sensitivity to magnetic susceptibility distributions, and dependence of iDQC signals on microstructures) and experimental parameters (field strength, pulse timing, coherence selection, detection method). These aims are achieved via research designs and methods in development of optimal iDQC imaging techniques with high SNR and unique contrast characteristics, guided by theoretical analyses and computer simulations, and validated with measurements in phantoms and rat brains at 1.5 9.4 and 14T, and brains of normal human volunteers at 1.5T. Our pulse sequence optimization will be approached from signal excitation, signal detection, and image post-processing, based on the unique characteristics of iDQC signals. The outcome of this study should lead to quantitation of essential factors for iDQC imaging contrast, and much improved imaging techniques applicable for a variety of novel applications at different field strengths.
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2002 — 2003 |
Zhong, Jianhui |
R21Activity Code Description: To encourage the development of new research activities in categorical program areas. (Support generally is restricted in level of support and in time.) |
Idqc Mr Imaging of Tumor Pathophysiology @ University of Rochester
DESCRIPTION (provided by applicant): MR imaging has been used extensively in clinical practice for tumor diagnosis. A wide variety of functional MRI techniques have also been developed to non-invasively assess tumor flow and oxygenation. In particular dynamic contrast enhancement (DCE) MRI has been shown to correlate well with tumor angiogenesis. BOLD effects have also been used to measure changes due to blood oxygenation and flow in tumor studies. With careful experimental design, BOLD effects may also provide quantitative information about oxygen saturation. Recently we have been developing a novel MR imaging technique based on intermolecular double-quantum coherences (iDQCs), which is inherently more sensitive to some physical processes relevant to tumor physiological characterization. In this application, we propose three different types of MRI measurements based on iDQCs, which will provide more sensitive and specific characterization of tumors in terms of: (1) oxygenation; (2) spatial distributions of microvessels at spatial resolutions far below conventional MRI; and (3) necrotic fraction. In the this phase, iDQC imaging methods suitable for tumor characterization will be developed and compared with conventional SQC MRI. Experimental murine tumor models, MCA-35 and MCA-4, which have been extensively characterized by the co-PI, Dr. Fenton, with immunohistochemical techniques, will be used for iDQC MR imaging on a 9.4T MR scanner. Histograms of physiological parameters measured with iDQC imaging will be compared to results from immunohistochemical measurements and conventional SQC MR/. Correlation will be sought in selected regions in the tumor core and periphery, as well as normal tissues. In the next phase, methods for multispectral analysis of images will be developed to address the multi-dimensional nature of tumor pathophysiology with integrated data from oxygen saturation, microvascular distribution, and tumor necrotic fraction measurements. Spatial correlation between MRI and immunohistochemical images for quantifying blood vessel distribution and oxygen saturation will also be pursued in this phase. Response to increased oxygen and effects of radiation therapy on tumor oxygenation and angiogenesis will be studied to validate the utility of new iDQC imaging techniques. The novel iDQC MR imaging proposed in this study will provide enhanced sensitivity and specificity for measurements based on the BOLD effect, and provide a new measurement for tumor vascularity complementary to conventional DCE techniques. Since the iDQC techniques proposed in this application do not involve changes in hardware, they can be translated into clinical applications relatively quickly once the methods are carefully validated.
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2009 |
Zhong, Jianhui |
S10Activity Code Description: To make available to institutions with a high concentration of NIH extramural research awards, research instruments which will be used on a shared basis. |
Upgrade of a 3t Siemens Trio Mri Scanner At the University of Rochester @ University of Rochester
DESCRIPTION (provided by applicant): The goal of the present NCRR proposal to the SIG program is to obtain resources for the upgrade of a current research-dedicated 3T Siemens MRI scanner that was purchased with NSF and private foundation funds and dedicated in September of 2004. When this scanner was purchased, it was state-of-the-art and it has provided outstanding service to the broad research community at the University of Rochester (and neighboring institutions). As MR technology continues to advance, however, the scanner is falling behind the curve of cutting-edge image acquisition. Limitations include the speed of acquisition, spatial resolution, real-time fMRI, and compensation for patient motion and image artifacts corrections. In addition, the scanner has shifted from a focus on neuroimaging to a broad array of structural, functional, diffusion/perfusion, and spectroscopic modalities applicable to cancer, orthopaedic and musculoskeletal research, to name just a few new user groups. Thus, it has become important to upgrade the scanner to enable specialized coils to conduct whole-body imaging without repositioning the patient. The specific upgrade that is requested from Siemens, called TIM (Total Imaging Matrix), consists of hardware (RF coils and receivers, gradients, and new computers) and software (new pulse sequences and post-processing tools) that improve the speed of image acquisition, improve the spatial resolution of both structural and functional scans, add the capability of obtaining real-time fMRI, reduce susceptibility artifacts, and provide coils for whole-body scanning. This upgrade will not only enhance on-going research projects but will expand the user-base to include new investigators who otherwise were unable to benefit from the current scanner. Current projects include studies of neuroimaging, cancer imaging, and orthopaedic imaging. It is important to note that the University of Rochester has made substantial commitments to the 3T imaging center in the form of space renovations (nearly $1 million) and on-going operating budget (over $500,000 per year). The proposed upgrade to the 3T scanner complements a broader strategic plan for imaging at the University of Rochester that has already resulted in three tenure-track faculty hires and several additional faculty hires (one outstanding offer and several planned for the next few years). PUBLIC HEALTH RELEVANCE: The upgraded scanner will significantly enhance a broad range of new basic and translational research projects at the University of Rochester. The basic research projects are aimed at fundamental aspects of how the brain mediates complex behaviors such as vision, language, and learning, and the translational research projects are aimed at the early diagnosis of disease, the assessment of disease states prior to treatment, and the adjustment of treatment regimes for optimal outcome. This broad range of studies of normal and pathological states will benefit greatly from improved anatomic, metabolic, and functional imaging, including neurological, cancer, and orthopaedic specializations.
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2020 — 2021 |
Zhong, Jianhui |
P50Activity Code Description: To support any part of the full range of research and development from very basic to clinical; may involve ancillary supportive activities such as protracted patient care necessary to the primary research or R&D effort. The spectrum of activities comprises a multidisciplinary attack on a specific disease entity or biomedical problem area. These grants differ from program project grants in that they are usually developed in response to an announcement of the programmatic needs of an Institute or Division and subsequently receive continuous attention from its staff. Centers may also serve as regional or national resources for special research purposes. |
Translational Neuroimaging & Neurophysiology Core @ University of Rochester
PROJECT SUMMARY Both new investigators with an interest in testing IDD-related hypotheses and experienced investigators who may wish to expand their research portfolios to address important IDD-related issues often find that there are structural barriers to entry into a new research path. High costs of modern imaging techniques, the specialized technical aspects of experimental design, data acquisition and analysis, as well as working with new patient populations can each constrain execution of important translational research. The purpose of the Translational Neurophysiology and Neuroimaging Core (TNN) is to provide access to a set of modern (if complex) tools, access to the professional expertise so that use of these tools can be productive, and access to an intellectual environment that encourages and supports new and ongoing research on IDDs. To accomplish these important goals, the TNN has a set of aims that include providing UR-IDDRC members access to human and small animal neuroimaging tools (3T and 9.4T MRI), human and small animal electroencephalography (EEG), Mobile Brain/Body Imaging, and access to pilot funding to defray the costs of using these tools to jump-start new IDD research. TNN faculty and staff will consult with investigators on the design of the experiment, assist with the implementation of protocols and train investigators and/or their trainees (postdocs and students) to perform the data processing and analyses. A monthly users group meeting also allows new investigators to learn about current protocols, capabilities and ongoing projects that might synergize with their own proposed work, and to develop collaborative relationships with other TNN investigators. In addition to this general support for UR-IDDRC members, the TNN core also supports the proposed research project ?Bridging the translational divide from cells to patients: toward reliable neuro-markers of Batten disease.? Aim 1 of the research project proposes to investigate auditory processing in children with Juvenile Neuronal Ceroid Lipofuscinosis in an effort to construct a neurophysiological biomarker of disease progression. Aim 2 of the research project proposes develop an identical EEG-based neuromarkers in murine models of Batten disease. The TNN serves as the hub for murine model EEG and also human EEG in people with and without IDDs. The facilities and services described in this core will be key elements to successful completion of the Aims of the research project.
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