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Fast MRI methods
Kořínek, Radim ; Gescheidtová, Eva (referee) ; Bartušek, Karel (advisor)
This thesis deals with comparison of rapid and conventional methods used in MRI (Magnetic Resonance Imaging). There is a description of imaging methods such as EPI (Echo Planar Imaging), Ultra-fast GRE, FSE (Fast spin echo) as well as a snapshot-FLASH and FISP (Fast Imaging with Steady Precession). Experimental part of this thesis deals with the rapid FSE (Fast Spin Echo) method. Especially is explained and assembled an algorithm for proper compilation of data from the FSE method. This algorithm allows us to evaluate the images from the FSE method. This method is examined in detail (in terms of impact parameters) and compared with traditional conventional methods. Finally, the individual images are evaluated, and the best parameters for FSE method are identified.
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Optimization of MR acquisition parameters for the measurement of small objects
Pecháček, Libor ; Přinosil, Jiří (referee) ; Gescheidtová, Eva (advisor)
The subject of my thesis is a design of the methods optimizing, the acquisition of MR signals when small objects measure. The thesis is divided into several parts in order to give a deeper knowledge of the problem. The first part focuses on the theory associated with NMR (Nuclear Magnetic Resonance) and SNR (signal-to-noise ratio). The practical verification of the theory follows. The conclusion of this work is focused on MR images filtering by use of wavelet transform to suppress a noise in the image. The method optimization of MR acquisition parameters for the measurement of small objects is then distributed to the entire work.
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Susceptibility weighted magnetic resonance imaging (SWI)
Bačovský, Jaromír ; Bartušek, Karel (referee) ; Starčuk, Zenon (advisor)
Susceptibility weighted magnetic resonance imaging (SWI) seems to be a very promising method usable in the diagnosis of a number of clinical and biomedical applications. Difusse axonal injuries and neurodegenerative diseases to name a few. The goal of my bachelor's thesis was to study the principal methods of magnetic resonance imaging with particular emphasis on susceptibility weighted imaging. Then use this theoretical knowledge for practical implementation of the SWI method to 4,7T/200mm NMR system located at Institute of Scientific Instruments of the ASCR, v.v.i. It was necessary to create an image calculated software, which is capable of enhancing contrast caused by magnetic susceptibility differences as they manifest themselves in local phase changes between tissues. Few basic problems had to be solved. The phase image was filtered by a high pass filter, a Phase Mask was created from adjusted image, which is generated from phase unwrapped image. To varify the SWI method, samples were designed, which have the desired magnetic properties. During the initial phase of experimenting, hen's eggs were used and then citrus fruits with nanoiron, CaCl2, Zn and AgCl. We investigated basic parametres and settings of the MRI measurements that affect final susceptibility weighted image.
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Development of Imaging Methods and its Importance to Biomechanics
Sedláček, Tomáš ; Houfek, Martin (referee) ; Florian, Zdeněk (advisor)
The main objective of this bachelor thesis is to collect all available literature, from which can reader obtain basic knowledge of imaging methods. The methods are divided by its origin into four categories: x-rays, magnetic resonance, ultrasound and nuclear medicine. Each of them is described from the historical, physics and technological view. At the end the importance of each method to medicine and biomechanics is summarized.
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Významné kroky v MRI
Bartušek, Karel
MRI is one of the leading medical diagnostic techniques. The lecture presents the basic important steps in the development of MRI and its application possibilities.Development of the field MR in ISI Brno began in 1960. Initially developed instrumentation of high resolution spectroscopy. Currently NMR group focuses on the development of measurement methods and technologies for biomedical and also technical applications of nuclear magnetic resonance and to the application of MR techniques in preclinical, particularly translational research utilizing mouse and rat animal models of neurologic, psychiatric and oncologic diseases.
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Compressed sensing for MRI perfusion imaging
Daňková, M. ; Rajmic, P. ; Jiřík, Radovan
Perfusion MRI is a diagnostic method in medicine. The signal captured from the affected area can be described by the curve of lognormal distribution. The standard way of obtaining the measurements is very slow and does not comply with today's challenging requirements. Using compressed sensing, we propose to acquire much less coefficients, having minimal effect on the signal reconstruction (using the assumption that the data is a sum of low-rank matrix and sparse matrix in row spectrum).
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Electrochemistry of Potential Eu MRI Complexes
Gál, Miroslav ; Sokolová, Romana ; Kielar, P.
Properties of the several potential contrast agents for magnetic resonance imaging (MRI) with Eu(III)/Eu(II) redox couple were investigated by means of the electrochemical methods. Cyclic voltammetry, phase sensitive AC voltammetry, and DC polarography were utilized to elucidate the mechanism of the reduction/oxidation of Eu ion in the presence of these compounds. Moreover, the stability constants of the Eu(II)-MRI agent complexes were also determined. Some suggestions on the chemical structure of the potential contrast agents for MRI are also made.
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