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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.
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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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Modelling in perfusion MR imaging
Válková, Hana ; Jiřík, Radovan (referee) ; Kratochvíla, Jiří (advisor)
This thesis deals with the magnetic resonance perfusion data analysis especially DCEMRI. In its introduction the thesis describes the problem of DCE-MRI data aquisition, the necessity of appropriate contrast agent and basic principles of perfusion analysis. The dynamic behavior of contrast agent vascular distribution can be described by arterial input function (AIF). The shape of the curves close to the area of interest is affected by dispersion which is called vascular transport function (VTF) due to the distribution of the contrast agent to the region of interest. Finally the tissue residual function describes system behavior of tissue. The practical part of the diploma thesis is aimed at implementation of model curves AIF, VTF and TRF. Furthermore, a simulation program was created for easy manipulation with introduced models moreover the program is used to perform an estimation of perfusion parameters based on nonblind deconvolution. The method is validated on synthetic data and illustrated on clinical data of the renal cell carcinoma patient.
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Measurement of Dialyser-Membrane Diffusion Coefficient
Kašák, Pavel ; Bartoš, Michal (referee) ; Jiřík, Radovan (advisor)
This thesis focuses on the measurement of diffusion coefficient of dialysis membrane. The first part describes possibilities of membrane modelling. Basic models, which allow us to determine the basic characteristics of dialysis membranes like permeability and diffusion coefficient, are described. Next chapter deals with basic types and properties of membranes. The main part focuses on making the experimental installation, which is used to simulate permeance of contrast agent, used in DCE-MRI, through dialysis membrane. The last theoretical chapter describes calculations used to estimate diffusion coefficient. Practical part of this thesis uses a designed experimental installation for estimation of diffusion coefficient for two contrast agents Gadovist® and Multihance®.
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DCE-MRI Acquisition Methods
Kudlička, Petr ; Kratochvíla, Jiří (referee) ; Jiřík, Radovan (advisor)
In my master’s thesis I describe basics of magnetic resonance measurement. I focus on methods of DCE-MRI with T1 weighting image. I mention some basic contrast agents which are used in MRI imaging. I describe some of pulse sequences which are used in experimental part of my thesis. There I measure contrast in the sample. The measurement is performed in accordance with an acquisition protocol I have proposed. The experiment part was realized on 1.5 T magnet at Masaryk Oncological Institute in Brno. I improved software which is use to research of MR IR TurboFLASH’s data and made software which is use to evaluation perfuse analysis ours measured sequences. At the end I made a discussion about gained facts.
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Registration of Ultrasound Image sequences
Kubica, Roman ; Mézl, Martin (referee) ; Jiřík, Radovan (advisor)
The result of this thesis, focused on medical image registration, is an automatic image registration algorithm. It is constructed to be used on real ultrasonography images, created by perfusion imaging. In its introductory part, the thesis deals with registrations methods, next it describes types of optimization principles and single criteria functions served to determine correct image transformation. Based on the theoretical part, there are realized three optimization algorithms using three criterial functions, which served to registration of provided ultrasonography sequences. These algorithms are tested and results are passed on analysis, on its ground are judged its advantages and disadvantages.
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MRI Acquisition of Image Sequences for Preclinical Perfusion Imaging
Krátká, Lucie ; Bartoš, Michal (referee) ; Jiřík, Radovan (advisor)
The task of this thesis is to study methods for the acquisition perfusní imaging based on dynamic MR imaging with T1 contrast. It describes methods of measurement of T1 relaxation time and the possibility of evaluating the results. It further describes the phantoms and their use. And it is here mentioned for the dynamic acquisition protocol perfusní imaging. There is also described in detail created a program for automatic control of the NMR system. In the experimental measurements are performed on static and dynamic phantom, are also evaluated perfusion parameters from the Flash sequence.
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Image Formats
Wolanský, David ; Bartoš, Michal (referee) ; Jiřík, Radovan (advisor)
The thesis deals with a detailed analysis of the GIF file format. It is divided into two basic parts, theoretical and practical. The theoretical part includes a thorough analysis of the internal file structure, i.e. the description of the individual block types, of which the file consists. Each block-type characteristic includes properties and a detailed description of its individual items. This part also includes a brief description of the most common compression methods applied in the field of image compression. The practical part includes the design and implementation of an edutainment application for synoptic viewing of the internal structure for a chosen GIF file and its parameters. The implementation of the application covers algorithms for selection of individual block types and realization of a graphical user interface.
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MRI Acquisition and Preprocessing of Image Sequences for Clinical Perfusion Imaging
Krchňavý, Jan ; Bartoš, Michal (referee) ; Jiřík, Radovan (advisor)
This thesis describes the theory for static and dynamic magnetic-resonance imaging using contrast agents affecting T1 relaxation time. The available acquisition methods in the specified facility of Masaryk Oncological Institute in Brno are described. The sequences for subsequent experimental measurements are selected. The used phantoms are described. Acquisition protocol for measuring is described briefly and the evaluation method for the measured data is suggested. The best acquisition sequence and a method of measurements is chosen influenced by estimation of relaxation time T1, sensitivity and signal to noise ratio. Perfusion analysis is executed and perfusion parameters are calculated. The work was supported by the European Regional Development Fund and the State Budget of the Czech Republic (RECAMO, CZ.1.05/2.1.00/03.0101).
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