Download or read book Whole Brain Isotropic Arterial Spin Labeling Magnetic Resonance Imaging in a Transgenic Mouse Model of Alzheimer s Disease written by James S. Curtis and published by . This book was released on 2008 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Whole Brain Isotropic Arterial Spin Labeling Magnetic Resonance Imaging in a Transgenic Mouse Model of Alzheimer s Disease written by James S. Curtis and published by . This book was released on 2008 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Neuroimaging biomarkers in Alzheimer s disease written by Samuel Barrack and published by iMedPub. This book was released on 2013-10-20 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: In view of the growing prevalence of AD worldwide, there is an urgent need for the development of better diagnostic tools and more effective therapeutic interventions. Indeed, much work in this field has been done during last decades. As such, a major goal of current clinical research in AD is to improve early detection of disease and presymptomatic detection of neuronal dysfunction, concurrently with the development of better tools to assess disease progression in this group of disorders. All these putative correlates are commonly referred to as AD-related biomarkers. The ideal biomarker should be easy to quantify and measure, reproducible, not subject to wide variation in the general population and unaffected by co- morbid factors. For evaluation of therapies, a biomarker needs to change linearly with disease progression and closely correlate with established clinico-pathological parameters of the disease. There is growing evidence that the use of biomarkers will increase our ability to better indentify the underlying biology of AD, especially in its early stages. These biomarkers will improve the detection of the patients suitable for research studies and drug trials, and they will contribute to a better management of the disease in the clinical practice. Indeed, much work in this field has been done during last decades. The vast number of important applications, combined with the untamed diversity of already identified biomarkers, show that there is a pressing need to structure the research made on AD biomarkers into a solid, comprehensive and easy to use tool to de deployed in clinical settings. To date there are few publications compiling results on this topic. That is why when I was asked to address this task I accepted inmediately. I am happy to present you a bundle of the best articles published about biomarkers for Alzheimer’s disease in recent times.
Download or read book Advanced Magnetic Resonance Imaging Techniques in the Diagnosis of Alzheimer s Disease Ad and Evaluation of Ad Pathogenesis in an Aging Brain written by Ka-Fung Henry Mak and published by Open Dissertation Press. This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Advanced Magnetic Resonance Imaging Techniques in the Diagnosis of Alzheimer's Disease (AD), and Evaluation of AD Pathogenesis in an Aging Brain" by Ka-fung, Henry, Mak, 麥嘉豐, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Background: The impact of Alzheimer's disease (AD) on society's resources and manpower has been forecasted for more than a decade, and recent statistics across the globe reveal that it is forthcoming. Pioneering work since 1980s confirmed the pathological hallmarks of the disease, such as neuritic plaques, neurofibrillary tangles, amyloid-β peptides, and microtubule-associated tau proteins. There are many gaps in the full appraisal of this complex disease, which possibly begins early in life in susceptible individuals and present at different severity and speed. In current thesis, advanced magnetic resonance imaging (MRI) techniques were evaluated for their efficacy in diagnosis, and in exploring AD pathogenesis. Methods: In MRI volumetry/perfusion and diffusion studies, 20 and 18 AD subjects (different cohorts) were recruited respectively from the memory clinic of a University hospital, while 20 and 18 cognitively normal older adults (CN) were recruited respectively from elderly centers, community and university volunteers, as well as 17 young adults in the diffusion study. In MR Spectroscopy (MRS), 30 healthy volunteers of 3 different age ranges (20-39, 40-59, 60-89) were recruited. All studies were performed using a 3-tesla MRI scanner. For MRI volumetry, a standardized T1-weighted 3D volumetric Fast Field Echo sequence, and for pulsatile Arterial Spin Labeling (ASL), a Look-Locker-based echo-planar imaging sequence was employed. Single-shot echo-planar diffusion weighted imaging was used to examine white matter (WM) integrity; diffusion sensitizing gradients (b = 800 s/mm2) applied in 16 directions, and one additional image without diffusion gradient (b0 = 0 s/mm2). Single voxel MRS was performed in the limbic regions, with point resolved spectroscopy for volume selection and excitation for water suppression. Results: Voxel Based Morphometry with Diffeomorphic Anatomical Registration using Exponentiated Lie algebra and standard registration has similarly high efficacies as manual hippocampal volumetry in discriminating AD from CN. Using pulsatile ASL, we found impairment of hemodynamic parameters other than cerebral blood flow (CBF) in moderate AD, indicative of underlying vascular abnormality. Combined MR hippocampal volumetry and ASL CBF was superior to single measure in AD diagnosis. Using diffusion tensor imaging (DTI) techniques, parallel evidence of anterior WM disintegrity in normal elderly, and more extensively in the AD was found. AD showed further loss of WM integrity in the posterior brain regions, and such WM disintegrity may result from demyelination. In aging, we found increased choline and creatine, and N-acetyl-aspartate in cingulate gyri, which might suggest glial proliferation and neuronal hypertrophy respectively. Discussion: A 'one-stop-shop' study combining structural and perfusion MRI has improved efficacy in discriminating AD from CN. DTI showed possible WM retrogenesis in normal aging and AD, although ischemic effect on WM cannot be ruled out. Our MRS study highlighted metabolic changes with age, which could be compensatory to an increased energy demand coupled with a lower CBF. Neuroimaging is likely to have a great impact on early diagnosis of AD, which will benefit patient care, prognostication and future therapy. Hopefully, insights into the physiol
Download or read book Arterial Spin Labeling Magnetic Resonance Imaging and Functional Synchrony of Blood Oxygen Level Dependent Signal Analysis in Early Detection of Alzheimer s Disease Onset written by Guofan Xu and published by . This book was released on 2006 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Functional Magnetic Resonance Imaging of the Murine Brain Application to a Transgenic Model of Alzheimer s Disease written by Thomas Müggler and published by . This book was released on 2002 with total page 189 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characterization of the Hemodynamic Profile of Early Alzheimer s Disease Via Arterial Spin Labeling Magnetic Resonance Imaging written by Simone Chaudhary and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cell type Specific Investigation of the Basal Forebrain with FMRI in Healthy and Alzheimer s Disease Mice written by Mazen Asaad and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The brain is a complex and vastly interconnected structure. Understanding how its different networks interact under physiological and pathological conditions has long been a difficult endeavor. However, technological advancements over the past few decades has led to the advent of optogenetic functional magnetic resonance imaging (ofMRI), through which we are now able to manipulate specific circuits and monitor the functional consequences throughout the entire brain. Thanks to developments in transgenic mouse models, we are able to target such circuits not only with spatial and temporal specificity, but neurochemical as well. The work presented in this dissertation combines these technologies to interrogate the functional roles of different cell types in the basal forebrain. The basal forebrain is a large and diverse brain region in itself, and as such it is implicated in a number of normal physiological processes such as sleep, attention, memory, and motivation. Additionally, it is one of the key regions prone to dysfunction in Alzheimer's disease, the leading cause of dementia today and a problem that has eluded proper understanding since its discovery over 100 years ago. Historically, much of the work examining the connectivity of the basal forebrain has been limited to either the functional relationships of a small number of nodes, or it has tried to identify brain-wide anatomical projection patterns. With ofMRI, this work can be extended further by combining functional connectivity with brain-wide projection mapping. We used ofMRI to examine the brain-wide functional consequences of stimulation of the three major cell types of the basal forebrain: cholinergic, GABAergic, and glutamatergic neurons. We found that all three cell types led to robust but distinct responses throughout cortical and subcortical areas. Cholinergic stimulation was restricted to the brain hemisphere ipsilateral to stimulation, in line with much of what has been found anatomically for basal forebrain inputs and outputs. However, GABAergic and glutamatergic stimulation resulted in bilateral activity implying a key distinction between functional and anatomical projections. We followed up ofMRI with in vivo extracellular electrophysiology in the ventral pallidum, somatosensory cortex, central thalamus, and zona incerta in order to better characterize the downstream consequences of cell-types specific basal forebrain activation. Additionally, we looked at the cholinergic basal forebrain in old mice with and without the APP/PS1 transgene, a model of Alzheimer's disease. In older mice, we found a weakened response to cholinergic basal forebrain stimulation, most notably in the somatosensory cortex where a significant cluster of negative BOLD signal disappeared relative to the young cohort. Interestingly, this cluster of activity was preserved in the APP/PS1 mice. While surprising, this finding is in line with a few recent studies examining brain areas that are particularly resistant to dysfunction in Alzheimer's disease, which includes the somatosensory cortex. More research in this area could open up new avenues for understanding what leads to differences in disease vulnerability that may elucidate the underlying pathological mechanisms as well as future treatment options. Taken together, the work presented here highlights the power of mapping cell-type specific functional circuits with ofMRI and adds a wealth of new information to our understanding of both the basal forebrain and Alzheimer's disease.
Download or read book Investigation of a Transgenic Model of Alzheimer s Disease the TASTPM Mouse Using Magnetic Resonance Spectroscopy and Matrix Assisted Laser Desorption Imaging written by Duncan Matthew Forster and published by . This book was released on 2011 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book In Vivo Magnetic Resonance Imaging and Spectroscopy of Alzheimer s Disease in Transgenic Mice written by Niels Braakman and published by . This book was released on 2008 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monitoring Alzheimer s Disease in Transgenic Mice with Ultra High Field Magnetic Resonance Imaging written by and published by . This book was released on 2013 with total page 143 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Multimodal Magnetic Resonance Imaging in Alzheimer s Disease Mouse Models written by Matteo Grudny and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Alzheimer's disease (AD) is primarily thought to impact cognitive and memory function in patients. However, Apathy and depression are two of the most prevalent symptoms diagnosed in those impacted by AD and mild cognitive impairment (MCI). Current evidence suggests that starting in the early preclinical stage of Alzheimer's disease, the function of vulnerable brain regions and the communication between brain areas involved in reward and memory processing become dysregulated. This project will provide new insights on the structural and network connectivity dysregulation that manifests in AD, using magnetic resonance imaging (MRI) methods to investigate the amyloidogenic 5xFAD and BXD mouse models of Alzheimer's disease.
Download or read book Magnetic Resonance Imaging Techniques for Visualising the Development of Alzheimer s Disease like Neurofibrillary Tau Pathology in Animal Models written by Ioannis Lavdas and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes the development of magnetic resonance imaging (MRI) techniques to visualise neurofibrillary tau pathology in transgenic mice. Neurofibrillary pathology is a prominent pathological feature of Alzheimer's disease (AD) and is closely correlated to cognitive impairment and dementia. 19F and 1H MRI methods were developed with a 4.7 T preclinical system. To facilitate these experiments, RF saddle coils were designed and constructed that show good agreement with theoretical SNR calculations and produce uniform B1 fields. A copper wire surface coil, incorporating active decoupling electronics, was built to increase the sensitivity of 19F and 1H mouse brain experiments. A stripline transmission line resonator (TLR) was also developed as a surface coil receiver and because it does not need tuning and matching adjustments, it reduces experimental set up times significantly. An ultra-short echo time (UTE) pulse sequence was developed for imaging 19F compounds, designed to attach to sites of tau pathology in the brain and which were known to exhibit very short T2 relaxation times. Ex vivo, 19F MRI experiments using these compounds indicated low penetration of the blood brain barrier and a tendency for precipitation. An RF spoiled, short TE 3D gradient echo pulse sequence was optimised to produce artefact-free T1-weighted images of the mouse brain. Measurements from a preliminary study using high resolution, T1-weighted MRI showed that the ventricular areas of a control mouse were not appreciably different from those of a transgenic mouse. Software was developed to generate automated T2 brain maps from spin echo MRI data sets and was used to compare T2 relaxation times between a control and a transgenic mouse. This experiment showed that the T2 relaxation times of the tau transgenic mouse brain were prolonged when compared to those of a control mouse.
Download or read book Measurement of Cerebral Blood Flow Using Arterial Spin Labeling Method Across Lifespan written by Ciwen Wang and published by . This book was released on 2015 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt: Arterial Spin Labeling (ASL) is one family of perfusion-weighted contrast imaging techniques of Magnetic Resonance Imaging (MRI) that measures cerebral blood flow by labeling spins in arterial blood with inversion and then waiting for a certain period of time for the labeled arterial blood to enter the imaging plane, and then acquiring MR image at the image plane. In compare with PET, ASL is a noninvasive new technology. But as a new technology, it is not very commonly used because of the relatively low signal to noise ratio, less robust mechanism, and more important, there is no standard for clinical applications. One goal of this study is to find out the optimal imaging processing way and parameters for ASL processing. The other goal is to find the relationship between CBF and age. There are 173 subjects, with 107 female subjects and 66 male subjects. Pseudo-continuous ASL (PCASL) was used as labeling sequence and multi-slice single shot 2D Echo-planar imaging (EPI) was used as MR image acquisition sequence. 40 pairs of control-labeled images were taken in order to increase signal to noise ratio. An MPRAGE T1 image was taken for each subject as brain structure reference. Label duration = 1650ms; post label delay = 1525ms; TR = 4260ms or 4210.8ms; TE=14ms. EPI factor = 35ms. Voxel size = 3x3x5 mm; FOV = 240x240x145 mm; slice number = 29. FSL which is a MRI image processing tool developed by Oxford was used in imaging processing. dcm2nii was used for DICOM to NIFTY conversion. MCFLIRT was used for motion correction. Trilinear interpolation was used in MCFLIRT. In spatial smoothing, a 3D Gaussian kernel with FWHM = 6mm was used. In M0 magnetization baseline calculation, the average magnetization of the whole brain of mean control image was used, so that the T1 recovery time was assumed to be the time from labeling to image acquisition of the middle slice (15th slice). The longitudinal relaxation time of blood was used as T1 value of the tissue. In Cerebral Blood Flow (CBF) calculation, also the longitudinal relaxation time of blood was used as T1 value of the tissue. A threshold of 0-300 was used on the CBF map. Voxels below 0 was assigned 0, and above 300 was assigned 300. CBF map was first co-registered on the T1 structural image of the same subject, and then, with the help of the high resolution T1, CBF map was normalized on MNI152 template. Relative CBF map was calculated by dividing the value of each voxel by the mean value of the whole brain CBF. The voxelwise analysis results (p
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2005 with total page 796 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Small Animal Imaging written by Fabian Kiessling and published by Springer. This book was released on 2017-05-22 with total page 871 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook is a practical guide to the use of small animal imaging in preclinical research that will assist in the choice of imaging modality and contrast agent and in study design, experimental setup, and data evaluation. All established imaging modalities are discussed in detail, with the assistance of numerous informative illustrations. While the focus of the new edition remains on practical basics, it has been updated to encompass a variety of emerging imaging modalities, methods, and applications. Additional useful hints are also supplied on the installation of a small animal unit, study planning, animal handling, and cost-effective performance of small animal imaging. Cross-calibration methods and data postprocessing are considered in depth. This new edition of Small Animal Imaging will be an invaluable aid for researchers, students, and technicians involved in research into and applications of small animal imaging.
Download or read book Magnetic Resonance Spectroscopy of Degenerative Brain Diseases written by Gülin Öz and published by Springer. This book was released on 2016-07-27 with total page 279 pages. Available in PDF, EPUB and Kindle. Book excerpt: The proposed book will act as a guide for scientists and clinicians to the unique information that MRS can provide. It will be a comprehensive overview of clinical and pre-clinical MRS applications and potential clinical utility of MRS biomarkers in degenerative brain diseases from leading experts in the field. MRS has proven to be a powerful complementary tool to MRI for the diagnosis and monitoring of disease progression and response to treatment because it can detect changes in cell density, cell type, and biochemical composition, not just structural changes. As the population in the developed world continues to age, neuroimaging for diagnosis, prognosis, and therapy monitoring of neurodegenerative diseases becomes increasingly important and there has been a recent surge of clinical and pre-clinical applications of MRS indicating that this technique can provide robust and non-invasive biomarkers of degeneration.
