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Acquisition, Modeling and Signal Processing in Ultrasound Perfusion Imaging
Mézl, Martin ; Kozubek, Michal (referee) ; Flusser,, Jan (referee) ; Jiřík, Radovan (advisor)
This work deals with possibilities of ultrasound perfusion analysis for the absolute quantification of perfusion parameters. In the theoretical part of this work are discussed possibilities of using of the ultrasound contrast agents and approaches for the perfusion analysis. New methods for the perfusion analysis are suggested and tested in the practical part of this work. The methods are based on convolutional model in which the concentration of the contrast agent is modeled as aconvolution of the arterial input function and the tissue residual function. The feasibility of these methods for the absolute quantification of perfusion parameters is shown on data from phantom studies, simulations and also preclinical and clinical studies. The software for the whole process of the perfusion analysis was developed for using in hospitals.
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Simulation of ultrasound sequences in contrast mode
Staňková, Jana ; Hesko, Branislav (referee) ; Harabiš, Vratislav (advisor)
This bachelor thesis deals with the principle of contrast imaging techniques for ultra-sound imaging. In the first part there are described basic principles and characteristics of ul-trasound waves for the understanding. It is also focused on ultrasound contrast agents used in contrast enhanced ultrasound imaging. The important part is the description of perfusion mo-dels with a focus obtain perfusion parametres and analyze perfusion curves obtained by mea-suring the ultrasound contrast agent over time. The second part is devoted to designing a pro-gram for generating simulated ultrasound images and description of the simulation of 2D ul-trasound tomograms.
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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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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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Modelling for ultrasound perfusion imaging
Hracho, Michal ; Šikner, Tomáš (referee) ; Mézl, Martin (advisor)
This thesis deals with the possibilities of determining perfusion parameters of vascular system, using contrast-enhanced ultrasound imaging, which is non-invasive method. Properties of ultrasonography and use of contrast agents are briefly summarized. The methods selected for perfusions analysis were Bolus-tracking¬¬, Burst-replenishment and both of them combined – Bolus&Burst. Parametric models based on these methods were created for modelling an approximation of set perfusion parameters with the use of blind deconvolution.
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Image Registration - Application in ophthalmology and ultrasonography
Harabiš, Vratislav ; Matula,, Petr (referee) ; Zemčík, Pavel (referee) ; Kolář, Radim (advisor)
Image registration is widely used in clinical practice. However image registration and its~evaluation is still challenging especially with regards to new possibilities of various modalities. One of these areas is contrast-enhanced ultrasound imaging. The time-dependent image contrast, low signal-to-noise ratio and specific speckle pattern make preprocessing and image registration difficult. In this thesis a method for registration of images in ultrasound contrast-enhanced sequences is proposed. The method is based on automatic fragmentation into image subsequences in which the images with similar characteristics are registered. The new evaluation method based on comparison of perfusion model is proposed. Registration and evaluation method was tested on a flow phantom and real patient data and compared with a standard methods proposed i literature. The second part of this thesis contains examples of application of image registration in~ophthalmology and proposition for its improvement. In this area the image registration methods are widely used, especially landmark based image registration method. In this thesis methods for landmark detection and its correspondence estimation are proposed.
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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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