National Repository of Grey Literature 145 records found  beginprevious126 - 135next  jump to record: Search took 0.01 seconds. 
Visualization and export outputs from functional magnetic resonance imaging
Přibyl, Jakub ; Gajdoš, Martin (referee) ; Slavíček, Tomáš (advisor)
Thesis discusses the principles and methodology for measuring functional magnetic resonance imaging (fMRI), basically the origin and use of BOLD signal types used experiments. Further attention is paid fMRI data processing and statistical analysis. Subsequent chapters are devoted to a brief description of the most common software tools used to analyze data from fMRI. The main section was to create a program in MATLAB with a detailed graphic user interface for easy visualization and export output from analyzes of fMRI data. The second half is devoted to describing the program developer and graphic user interface, including key functionality. The final section describes the application program with real data from clinical studies of dynamic connectivity and use in an international project APGem.
Fixation of the biological samples
Brachtl, Martin ; Jiřík, Radovan (referee) ; Krátká, Lucie (advisor)
The aim of thesis is acquaint with possibilities of fixation biological tissues. Choose a suitable tissue and fix it with formaldehyde and another fixator. Last but not least make measurements which determine effects of formaldehyde on the relaxation time of biological tissues. Mice brains were chosen as a suitable for tissues fixation. Measuring effects of formaldehyde and another fixator to relaxation time carried out at the Institute of Scientific Instuments Academy of Sciences of the Czech Republic.
Quantification of T1 for Preclinical MRI
Dvořáková, Lenka ; Macíček, Ondřej (referee) ; Jiřík, Radovan (advisor)
T1 mapping of myocardial tissue is important for diagnostics of myocardial fibrosis. Cardiac magnetic resonance imaging of small animals is challenging due to high heart and respiratory rates. Pulse sequences for T1 mapping are proposed in this thesis based on inversion recovery FLASH and Intragate FLASH. The sequence IR FLASH was compared to the reference sequence RARE on a static phantom. Both sequences were applied for measuring the myocardium of a rat. For T1 quantification a software in Matlab was developed. Using this software, T1 maps of rat myocardium were calculated.
Segmentation of Blood-Vessel Tree in Whole-Body MRI Data
Guricová, K.
The aim of this paper is to introduce a method of blood-vessel tree segmentation in 3D volume and the visualization of the processed data. The method is based on the detection of tubular structures which the blood-vessels resemble. The processing is based on the information that is carried in the derivatives of the original volume. Second derivatives of each voxel are computed and organized into a Hessian matrix. The used method is based on the calculation of the eigenvalues of this matrix for each voxel. Those eigenvalues carry the information of the structure shape. Based on this information, a new parametric volume is created that represents the ’vesselness’of each voxel. The processed volume is visualized with Visualization ToolKit.
Study of the influence of magnetic fields on biological tissue
Vlachová Hutová, Eliška ; Fiala, Pavel (referee) ; Bartušek, Karel (advisor)
The aim of this research is to explore the influence of magnetic field on early somatic embryos (ESEs) of spruce and pine. The magnetic field is gradual. This is important for the experiment, each cluster of ESE was exposed to magnetic field of different intensity. The resulting report of this experiment consists of the comparison between various methods of image analysis and the difference in growth of ESEs due to different exposure to magnetic field and surrounding temperature. Enclosed is a proposal of ESE size computing algorithm from a given image.
Optimization of method for susceptibility measurement
Jeništa, Petr ; Marcoň, Petr (referee) ; Bartušek, Karel (advisor)
The aim of this thesis is measure the specimens placed in field of MR tomograph, the measured data to evaluace the process and measurement errors. The theoretical part is focused on describing basic parameters of magnetic field, commissioning some older methods of measurement and design methods for the measurement of samples not issuing MR signal. There is performed modeling for the proposed Metod and the 1D, 2D and 3D environments using COMSOL Multiphysics. The practical part is the measurements samples in the tomograph the Institute of Scientific Instruments Academy of Science in Brno. The measured data are processed in Marevisi and Matlab programs. The MATLAB program is written for processing, analysis and data evaluation, after which it is possible to determine the value of the magnetic susceptibility of the selected samples. In conclusion of the work is the quantification accuracy of measurements.
Neuroinformatics: calibration methods in multicentric MR studies
Kovalčík, Tomáš ; Říha, Ivo (referee) ; Provazník, Ivo (advisor)
Work deals with methods of calibration of multi-center study of magnetic resonance imaging. Magnetic resonance is the phenomenon of the substance in a magnetic field of induction B0 delivers energy in the form of RF pulse with the Larmor frequency and thus to excite particles to higher energy levels. Calibration can be performed using the distinctive and homogeneous RF phantoms. Furthermore, we can perform calibration using image registration. To calibrate the images by registering the work described in the classical linear (affine) and nonlinear. Listed below are the simulators, which are also useful for modeling various artifacts.
Neuroinformatics and sharing data from medical imaging systems
Klimek, Martin ; Kubásek, Miroslav (referee) ; Provazník, Ivo (advisor)
The presented master's thesis deals with the issue of storing and sharing data from medical imaging systems. This thesis, inter alia, consists of organizational and informatics aspects of medical imaging systems data in multicentric studies containing MRI brain images. This thesis also includes technical design of a web-based application for image data sharing including a web interface suitable for manipulation with the image data stored in a database.
Numerical modeling of magnetic susceptibility influence to MR images
Julínek, Michal ; Fiala, Pavel (referee) ; Bartušek, Karel (advisor)
The numeric simulation of magnetic field of selected samples is made and resuled is compared with MRI measurement.
Errors in MRI methods for measuring diffusion coefficients
Uríča, Jozef ; Marcoň, Petr (referee) ; Gescheidtová, Eva (advisor)
Diploma thesis Errors in MRI methods for measuring diffusion coefficients a study of measurement of diffusion NMR methods, specifies the location, causes, origination diffusion coefficients. The main function of the program is to simulate changes parameters measurement of diffusion coefficients and allows for example only one gradient or runs down gradient pulses.

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