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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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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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Scaling of arterial input function in DCE-MRI
Holeček, Tomáš ; Kolář, Radim (referee) ; Kratochvíla, Jiří (advisor)
Perfusion magnetic resonance imaging is modern diagnostic method used mainly in oncology. In this method, contrast agent is injected to the subject and then is continuously monitored the progress of its concentration in the affected area in time. Correct determination of the arterial input function (AIF) is very important for perfusion analysis. One possibility is to model AIF by multichannel blind deconvolution but the estimated AIF is necessary to be scaled. This master´s thesis is focused on description of scaling methods and their influence on perfussion parameters in dependence on used model of AIF in different tissues.
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Measurement of cardiovascular parameters
Kratochvíla, Jiří ; Čmiel, Vratislav (referee) ; Kolářová, Jana (advisor)
The aim of the bachelor’s thesis is to get acquainted with the measurement of cardiovascular parameters, to realize the measurment of these parameters, to analyze them, show the statistic procedure of verifying hypotheses in this spere and finally the presentation of measured data including automatical detection of the heart rate from ECG signal in created program in Guide of Matlab system. On the basis of the theory was done the measurment on own suggestion with the Biopac system and with the quicksilver tonomether. The parameters, that were measured on the group of five people: ECG, blood pressure and the pulse frequency before and after the load. After the data processing was done the statistic analysis, the aim of this analysis was to show the procedure of verifying hypothesis, if and how are these measured parameters of cardiovascular system changing. After that the measured data were transported into Matlab system. The presentation of measured data (created program) contains the time domain and spectral analyses (using Fourier transform) of ECG signal, automatical detection of the heart rate from ECG signal, analysis of the heart rate variability (HRV) – tachogram together with detailed analysis of HRV spectra (spectra of heart rate variability – relating with parasympathetic and sympathetic activity), that are using in clinical practice too, just as the other measured parametres of the cardiovascular system.
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Dynamic Focusing in Ultrasound Tomography
Kratochvíla, Jiří ; Roleček, Jiří (referee) ; Jiřík, Radovan (advisor)
The aim of the master’s thesis, is to get acquainted with the dynamic focusing in conventional ultrasound systems, to modify this method for ultrasound computer tomography and to realize and interpret this modification on simulated and real data in a transparent graphic interface. The modification of the dynamic focusing was executed for the 3D ultrasound computer tomograph developed in Karlsruhe. Simulated data, that are necessary for focusing, were generated by existing program, which was adjusted. The new created program of the dynamic focusing was tested and evaluated with those simulated and real data.
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