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Showing 1 to 20 of 21 for “"Chemical Shift Imaging"”.
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N.M.R. chemical shift imaging
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Medical Engineering and Medical Physics, 1984.
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Simultaneous multislice spiral and EPI chemical shift imaging
… methods of 3D slabs used for MR Spectroscopy Imaging (MRSI) include long dead times in each TR. This dead time is necessary for magnetization moments' longitudinal relaxation, and so a good SNR efficiency. The fact that SNR is one of the dominant challenges that MRSI faces makes it an …
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Dynamic Chemical Shift Imaging For Image-Guided Thermal Therapy
Magnetic resonance temperature imaging (MRTI) is recognized as a noninvasive means to provide temperature imaging for guidance in thermal therapies. The most common method of estimating temperature changes in the body using MR is by measuring the water proton resonant frequency (PRF) shift. …
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Quantitative 1H N.M.R. chemical shift imaging of neuronal content
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1994.
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Präoperative Evaluierung von Transplantatnieren: Volumenselektive 31P-Magnet-Resonanz-Spektroskopie mittels Chemical Shift Imaging
… nicht <br>geeignet ist. Das Verfahren des Chemical Shift Imaging (CSI) erlaubt die Aufzeichnung von volumenselektiven 31P -Spektren. Hierbei wird unter Ausschluss des störenden Phosphates der <br>Perfusionslösung die gezielte Beurteilung von 31P –Spektren aus dem Nierengewebe möglich. Die …
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Improved magnetic resonance chemical shift imaging at 3 Tesla using a 32-channel integrated RF-shim coil array
In vivo chemical shift imaging is an imaging modality which uses the so-called chemical-shift phenomenon to quantitate brain metabolites spatially, therefore renders the study of brain metabolism and neurodegenerative diseases possible and eases diagnosis of tumors. However, the method is highly …
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Sequence Development and Expansion of Zero J-Modulation Echo-Planar Chemical Shift Imaging in Three Dimensions (3D ZJ-EPSI)
… a huge value. 3D Zero J-modulation Echo Planar Chemical Shift Imaging (3D ZJ-EPSI) is a fast MRS technique that can not only achieve all that was mentioned above, it can also provide additional detailed anatomical/pathological information due to its 3D nature. 3D ZJ-EPSI technique acquires …
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An NMR study of human brain tumours: Phosphorus chemical shift imaging in vivo and high resolution proton spectroscopy of biopsy samples.
… resonance (NMR). The localization technique, chemical shift imaging has been used to obtain phosphorus spectra of tumours in vivo. High resolution proton spectroscopy has been performed on biopsy samples and extracts of human brain tumours. To obtain the localized phosphorus spectra, one …
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Reconstruction algorithms for MRI
… reconstruction algorithms for Magnetic Resonance Imaging (MRI) that aims to increase the imaging efficiency. Algorithms that reduce imaging time without sacrificing the image quality and mitigate image artifacts are proposed. The goal of increasing the MR efficiency is investigated across multiple …
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Magnetic resonance spectroscopy: techniques and applications in thermometry and metabolite mapping
… and Hamming filters and the adaptation of chemical shift imaging from 2D to 3D is useful in obtaining more precise information. Herein, it is shown that both absolute and relative quanti cation can be improved through, respectively, frequency filters and increased dimensional acquisition.
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Clinically relevant magnetic resonance imaging and spectroscopic imaging development
… of this thesis, a single slab 3D fast spin echo imaging (3DFSE) method has been implemented and optimized. This involved sequence design and implementation, SAR considerations, parameter adjustments and clinical testing. The method can deliver 3D Tl or T2 weighted brain image with isotropic Imm3 …
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Etablierung und klinische Anwendung der 31P-Kernspinresonanzspektroskopie an Nierentransplantaten zur präoperativen Evaluierung der Organqualität im Vergleich zum klinischen Bild im postoperativen Verlauf
… ist die volumenselektive Spektroskopie (Chemical Shift Imaging, CSI) etabliert worden. Zur Auswertung der Spektren wurden das Frequency-Domain-Fitting und das Time-Domain-Fitting verglichen. <br>In den Ergebnissen der selektiven Nierenrinden- und Markspektroskopie zeigte sich ein der …
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Investigation of metabolism in glioblastoma patient-derived xenografts using deuterium metabolic imaging
… to treatment. Conventional anatomical imaging techniques provide morphological information, such as tumour size and perfusion. However, they do not provide any information on metabolic activity, which in treated tumours can precede anatomical changes. Position emission tomography (PET) …
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Imaging Glutamate In The Human Brain At Ultra-High Magnetic Field: Advances And Applications
… limited. Amongst the few options in the medical imaging toolbox are magnetic resonance spectroscopy (MRS) and a recently introduced specialized form of magnetic resonance imaging (MRI) known as glutamate-weighted chemical exchange saturation transfer imaging, or gluCEST. MRS, while providing good …
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Magnetic Resonance Studies of Three-Phase Heterogeneous Catalytic Hydrogenation Reactions
… The techniques developed aimed to elucidate the chemical composition inside the reactor and to provide a better understanding of the interactions of the reaction species with the catalyst material and reactor. Bulk and spatially resolved 2D NMR relaxation and diffusion measurements were used to …
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Magnetic resonance spectroscopic imaging using parallel transmission at 7T
Conventional magnetic resonance spectroscopic imaging (MRSI), also known as phase-encoded (PE) chemical shift imaging (CSI), suffers from both low signal-to-noise ratio (SNR) of the brain metabolites, as well as inflexible tradeoffs between acquisition time and spatial resolution. In addition, …
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In-Vivo Three Dimensional Proton Hadamard Spectroscopic Imaging in the Human Brain
Magnetic resonance spectroscopic imaging (MRSI) is a useful tool for obtaining information on the biochemical processes underlying various pathologies. A widely used multi-voxel localization method is chemical shift imaging (CSI) which uses gradients for phase encoding. Although simple to …
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Packed bed reactors at the pellet scale: magnetic resonance studies of hydrodynamics, mass transport and reaction
Packed bed reactors are widely used in the chemical and petrochemical industries to facilitate heterogeneous catalytic reactions. Despite the widespread use of packed bed reactors in industry, the flow, transport, and reaction phenomena occurring at the scale of individual catalyst pellets is …
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Development of Optimised Pulse Sequences for Magnetic Resonance Imaging of Tumour Metabolism
… efficient pulse sequences for hyperpolarised 13C imaging: Dynamic nuclear spin polarization of 13C-labeled cell substrates has enabled dynamic measurements of tissue metabolism in vivo using 13C MRSI. The principal limitation of the technique is the short lifetime of the hyperpolarisation, which …
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Investigating neuroinflammation in schizophrenia: a proton magnetic resonance spectroscopy (1H-MRS) and cytokine study
… All participants underwent a magnetic resonance imaging scan, which included magnetic resonance spectroscopy with voxels located in the anterior cingulate cortex (ACC) and left thalamus as well as a chemical-shift imaging 2-dimensional slice. Neurometabolites obtained included glutamatergic …
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