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Measurement of relaxation constants by use of magnetic resonance
Kořínek, Radim ; Bartušek, Karel (referee) ; Gescheidtová, Eva (advisor)
This bachelor’s thesis is dedicated to principles of magnetic resonance and measurement of relaxation times. At theoretical part all basics methods of measurement (SE-spin echo, GE-gradient echo, SR-saturation recovery, IR- inversion recovery) of relaxation times T1, T2 resp. T2* are shown. At practical part T1 and flip angles are carefully observed. In case of measurement of relaxation time T2, the FID signal acquisition after 90° RF pulse is sufficient. T2* time is set from absorbtion line. For measurement of transversal relaxation method SE (often called as Hahn spin echo –90° RF pulse is followed by next 180° RF pulse) can be used. With GE method, the T2* relaxation is observed. Measurement of relaxation time T1 using RF impulses and inclinable angles A, is described at chapter 3. Every magnetization components during RF impulses are deeply described by mathematical formulas. Other chapter of this bachelor thesis describes some functions from MATLAB and their fitness for approximation of signal. From every tested functions, the lsqcurvefit function would be the best. Iteration method is most fitting function for approximation of FID signal.
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Optimization of the MRI chicken embryos measurements
Sedláčková, Gabriela ; Dražanová, Eva (referee) ; Krátká, Lucie (advisor)
This thesis deals with optimization of MRI measuring of phantoms containing the chicken embryo. The theoretical part of thesis is dedicated to the MRI fundamentals and description of pulse sequences. In the next part the options of keeping and monitoring the temperature are being discussed. The thesis also deals with design and realization of phantoms which are used for measuring. A browser of images captured by MRI was programmed in Matlab environment. The program allows users to look through the images with different settings of pulses sequences or kind of phantom. The final part of thesis describes the anatomical structures of chicken embryo and discussion of collected results.
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Errors of diffusion measurements for MRI
Kavan, Pavel ; Rampl, Ivan (referee) ; Bartušek, Karel (advisor)
The Bachelor’s thesis is, at it’s begining, focused on the imaging and diagnostic techniques based on principles of magnetic resonance imaging. Nowadays, nuclear magnetic resonance belongs to reputable examing methods of variable molecule matters. Especially, due to multiinterval spin-echo PFGSE methods. Further in this thesis is spin-echo pulse sequence simulated in the data processing computer program Matlab. Simulations influencing error measurement of b-factor and diffusion are performed. These simulations could help to prevent appearance of measurement errors at some other experiments.
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Contrast MRI perfusion imaging
Šejnoha, Radim ; Harabiš, Vratislav (referee) ; Krátká, Lucie (advisor)
This semestral thesis is focused on contrast MRI perfusion imaging using method of Dynamic Contrast-Enhanced MRI. It describes basic principles of nuclear magnetic resonance and puls sequences used in DCE MRI. The thesis contains a part dedicated to dynamic contrast imaging of phantom with experimental NMR device located at the Institut of Scientific Instruments of the ASCR in Brno. Results of measurements are analyzed based on models and reached perfusion parameters are discussed.
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The effect of the MR pulse sequences on the measurement object temperature
Kosková, Markéta ; Jiřík, Radovan (referee) ; Krátká, Lucie (advisor)
This paper deals with the effect of the MR pulse sequences on the temperature of the measured object. The theoretical part is dedicated to basic principle of magnetic resonance, the selected pulse sequences and risks that are connected with MRI. There is also described the draft of the testing phantom and information about the measurement and record of temperature during MR measurement. In the experimental part the effect of RF coils, pulse sequences and parameters of pulse sequences are tested on drafted phantom with experimental MR device located at the Institut of Scientific Instruments of the AS CR in Brno. These findings are then tested on live laboratory mouse. All results are analyzed and used as default data for developed simulation program.
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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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Relaxation times in the polymer gel electrolytes by magnetic resonance methods
Jehličková, Lenka ; Kadlec, Radim (referee) ; Kubásek, Radek (advisor)
The purpose of this Bachelor’s thesis is measuring of gelly structure relaxation using magnetic resonance imaging. The first part closely describes the theory needed for upcoming measuring. There is explained basic physical principle of NMR and terms such as precession, Larmor frequency and RF pulses are established. The measuring instrument is also schematically introduced, as are its main parts and division in aspect of magnetic fields. The most important part is explanation and understanding of relaxation processes that happen during NMR. Individual sequences used for measuring of relaxation processes are demonstrated by the spin echo method, which is the basic building block of all successive methods. The second part is processing of results. Measuring of fall and spectre of given gelly samples is expressed as a function of time T2 on the sample solidification time.
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Contrast MRI perfusion imaging
Šejnoha, Radim ; Harabiš, Vratislav (referee) ; Krátká, Lucie (advisor)
This semestral thesis is focused on contrast MRI perfusion imaging using method of Dynamic Contrast-Enhanced MRI. It describes basic principles of nuclear magnetic resonance and puls sequences used in DCE MRI. The thesis contains a part dedicated to dynamic contrast imaging of phantom with experimental NMR device located at the Institut of Scientific Instruments of the ASCR in Brno. Results of measurements are analyzed based on models and reached perfusion parameters are discussed.
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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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The effect of the MR pulse sequences on the measurement object temperature
Kosková, Markéta ; Jiřík, Radovan (referee) ; Krátká, Lucie (advisor)
This paper deals with the effect of the MR pulse sequences on the temperature of the measured object. The theoretical part is dedicated to basic principle of magnetic resonance, the selected pulse sequences and risks that are connected with MRI. There is also described the draft of the testing phantom and information about the measurement and record of temperature during MR measurement. In the experimental part the effect of RF coils, pulse sequences and parameters of pulse sequences are tested on drafted phantom with experimental MR device located at the Institut of Scientific Instruments of the AS CR in Brno. These findings are then tested on live laboratory mouse. All results are analyzed and used as default data for developed simulation program.
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