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Perfusion analysis using DSC-MRI method
Minsterová, Alžběta ; Jiřík, Radovan (referee) ; Macíček, Ondřej (advisor)
This bachelor thesis deals with the DSC (Dynamic Susceptibility Contrast) method, which is one of the magnetic resonance imaging methods using a contrast agent. It describes the principle of the magnetic resonance imaging, other methods of MRI using the contrast agent are mentioned. It further contains the DSC-MRI method, common used sequences and the description of a procedure of an imaging by this method. This thesis also focuses on the implementation of a graphical application in MATLAB, which copes with the perfusion analysis and the visualization of perfusion maps.
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Image objects detection based on the feature points matching
Trávníček, Vojtěch ; Macíček, Ondřej (referee) ; Harabiš, Vratislav (advisor)
This paper is concerned in branch of computer vision. Methods for extracting feature points are presented as tools for image comparison and finding objects in images. Four methods are metioned which are compared with respect to their effectiveness and utilization. Algorythms SIFT and SURF are described as a state-of-the-arts. This paper also mentions methods for describing feature points and their comparison. Testing images are inserted as a tool for first testing of implemented algorythm. Finally, the implemented method SURF is described and tested with respect to several most relevant parameters.
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Comparison of the preclinical DCE-MRI perfusion techniques
Minsterová, Alžběta ; Jiřík, Radovan (referee) ; Macíček, Ondřej (advisor)
This diploma thesis deals with DCE-MRI (Dynamic Contrast-Enhanced Magnetic Resonance Imaging) thus one of the contrast magnetic resonance imaging methods. It describes the principle of conventional continuous DCE-MRI, which uses single bolus of contrast agent and further it focuses on the dual bolus contrast agent techniques, especially the interleaved acquisition. The graphical interface for processing Bruker systems data was made. Synthetic data were used to evaluate the influence of this method on the perfusion parameters estimation. Simulations proved that the further the second bolus is from the first one, the better results are. Simulations of acquisition interruption did not lead to the clear result. However, two statements, which are expected to lead to as good estimation of perfusion parameters as possible, were formulated
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Using multi-echo sequences in DSC-MRI
Černý, Štěpán ; Jiřík, Radovan (referee) ; Macíček, Ondřej (advisor)
The task of this thesis is to study the subject of perfusion analysis based on dynamic imaging with T2/T2* contrast. The focus was on the acquisition commonly used for DSC-MRI and especially in the acquisition pulse sequences that use images with different echo time, so called Multi-echo sequence. Principles of dynamic measurement by magnetic resonance imaging, the role of contrast agents and their influence on the relaxation times are described. It also describes the problems perfusion analysis, measurement and mathematical modeling parameters entering to the convolution dependency for getting perfusion parametersIn the experimental part is developed automatic algorithm to gain curves relaxation time T2 *. Next, the synthetic data are created and tested robustness estimate perfusion parameters against noise. In the next phase of work there are compared real scanned objects with using a conversion with T2 * and free of T2*. In the last phase of work is compared influence of length of used echo times on concentration curves and after perfusion analysis influence on resulting perfusion parameters.
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Batch processing of perfusometric MRI data
Filipová, Petra ; Macíček, Ondřej (referee) ; Jiřík, Radovan (advisor)
This diploma thesis deals with the DCE – MRI method (Dynamic contrast enhanced magnetic resonance imaging). Basic principle of magnetic resonance and pulse sequence is described. The diploma thesis focuses on the DCE method, especially on the description of the processing procedure by this method. Description of selected pharmacokinetic models is the part of this diploma thesis as well. Furthermore, description and realization of batch processing by PerfLab system is presented. For verifying purposes of the batch processing functionality real data were measured using created acquisition protocol, which is also part of the diploma thesis.
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Contrast enhancement for tissue discrimination and contrast nanoparticle detection by MRI
Bačovský, Jaromír ; Macíček, Ondřej (referee) ; Starčuk, Zenon (advisor)
Magnetic resonance imaging is a routine and powerful diagnostic technique capable of providing detailed information about the structure and composition of the tissues. This diploma thesis is concerned with the mechanisms of contrast origin and contrast modifications by molecular and nanoparticle contrast agents. First sections of the thesis summarize basic knowledge about pulse sequences and it aims to provide an overview on MRI contrast agent with a special emphasis on paramagnetic gadolinium contrast agents and superparamagnetic nanoparticles. The main purpose of this study is to develop the software called MRICalc, which is able to optimize contrast in MRI images. Based on analysis of signal formula of typical pulse sequences, MRICalc is able to propose the parameters of the pulse sequence for compartment-specific enhancement of the contrast. User chooses from the list of the samples and after calculation he obtains the values of echo time, repetition time and flip angle, all of which simultaneously seem to create the appropriate setting to enhance the contrast. MRICalc also allows to plot contrast function with respect to the chosen parameter. Software, including its graphical user interface, is designed in Python. The sample consists from solution of CuSO4 and distilled water was designed to verify the correct function of MRICalc. Sulphate represents a contrast agent. Preclinical MR system Bruker BioSpec 94/30 USR located at Institute of Scientific Instruments of the ASCR, v.v.i was used to measure contrast curve of FLASH pulse sequence, which is a typical representative of gradient echo. Results of the measurement were compared to the theoretical model provided by MRICalc.
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Design of Hearing Aids in LabVIEW
Macíček, Ondřej ; Tannenberg, Milan (referee) ; Sekora, Jiří (advisor)
This thesis contains the block diagram of hearing aid, anatomy description of human hearing system and description of most important physical values in this problematics of hearing and sound. There are analyzed several types of hearing tests for diagnosis of the hearing loss level and some types of algorithms, which fit the frequency characteristic of patient's hearing loss too. Further this thesis contains interactive program of hearing aid, which has implemented equations for sound equalization.
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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.
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Data Transfer via Ethernet
Kutílek, Miloš ; Macíček, Ondřej (referee) ; Sekora, Jiří (advisor)
This thesis deals with the transmission of information over the Ethernet network. In this work a suitable microcontroller and a communication module were selected. The Module provides data transfer from Ethernet to SPI bus. Furthermore an optimal digital temperature sensor DS1820 was chosen. Theoretically it describes the model TCP / IP and the Ethernet type network . In this thesis a block circuit diagram is created, further an electrical wiring diagram and a printed circuit board were constructed. In the programming environment BascomAVR a program is compiled, which is used to transfer information from the microcontroller via Ethernet to a website.
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Design of Flow, Temperature and Pressure Measuring System
Macíček, Ondřej ; Čížek, Martin (referee) ; Sekora, Jiří (advisor)
This master’s thesis contains complete design of the complex measuring system for temperature, pressure and flow. Objects of measuring are pressure in rabbit’s heart ventricle, flow of the saline through the heart and the temperatures of physiological solution. Work is interested in programming of microcontroller and program for LabVIEW environment, which is used to view and export relevant data related to measuring. Text also contains technical documentation of functional sample of measuring system.
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