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Statistical properties of ultrasound images in contrast mode
Věžníková, Romana ; Kolář, Radim (referee) ; Slávik, Vladimír (advisor)
The bachelor’s thesis is focused on properties of ultrasound images in contrast mode. First of all it describes the basic properties of ultrasound, the way in which the ultrasonic signals are generated, the parameters of ultrasound and ultrasonic imaging modes. Next part deals with harmonic and contrast imaging modes. This part explains principles of these modes as well as the usage of contrast agents and artefacts connected with ultrasound imaging in contrast mode. The thesis also shows the approximation of the amplitude probability density function of ultrasonic images and description of its single models, out of which is chosen the RiIG model (Rician Inverse Gaussian distribution) for approximation of ultrasound images in this case. To gain parameters of amplitude probability density function from ultrasonic data in contrast imaging mode is made the application using Matlab programming environment. Thereafter is the thesis focused on determining equations for dependences of RiIG distribution parameters on known concentrations of contrast agent for ultrasonic data captured in vitro. These equations are useful for determining the unknown concentration of contrast agent used in images captured in vivo and making its dilution function.
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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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Modelling for ultrasound perfusion imaging
Jakubík, Juraj ; Jiřík, Radovan (referee) ; Mézl, Martin (advisor)
This master thesis deals with the contrast agents and their application in the ultrasound perfusion analysis. It is focused on Bolus & Burst method which, as a combination of two approaches that have been used so far, allows an absolute quantification of perfusion parameters in the region of interest. Contrast agent concentration time sequence is modeled as a convolution of the parametrically defined arterial input function and the tissue residual funkction. Thesis discusses different mathematical models of these functions as well as the methods of the parameters estimation. The methods functionality is validated on simulated and also preclinical data.
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Modelling for ultrasound perfusion imaging
Jakubík, Juraj ; Jiřík, Radovan (referee) ; Mézl, Martin (advisor)
This master thesis deals with the contrast agents and their application in the ultrasound perfusion analysis. It is focused on Bolus & Burst method which, as a combination of two approaches that have been used so far, allows an absolute quantification of perfusion parameters in the region of interest. Contrast agent concentration time sequence is modeled as a convolution of the parametrically defined arterial input function and the tissue residual funkction. Thesis discusses different mathematical models of these functions as well as the methods of the parameters estimation. The methods functionality is validated on simulated and also preclinical data.
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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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Statistical properties of ultrasound images in contrast mode
Věžníková, Romana ; Kolář, Radim (referee) ; Slávik, Vladimír (advisor)
The bachelor’s thesis is focused on properties of ultrasound images in contrast mode. First of all it describes the basic properties of ultrasound, the way in which the ultrasonic signals are generated, the parameters of ultrasound and ultrasonic imaging modes. Next part deals with harmonic and contrast imaging modes. This part explains principles of these modes as well as the usage of contrast agents and artefacts connected with ultrasound imaging in contrast mode. The thesis also shows the approximation of the amplitude probability density function of ultrasonic images and description of its single models, out of which is chosen the RiIG model (Rician Inverse Gaussian distribution) for approximation of ultrasound images in this case. To gain parameters of amplitude probability density function from ultrasonic data in contrast imaging mode is made the application using Matlab programming environment. Thereafter is the thesis focused on determining equations for dependences of RiIG distribution parameters on known concentrations of contrast agent for ultrasonic data captured in vitro. These equations are useful for determining the unknown concentration of contrast agent used in images captured in vivo and making its dilution function.
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Contrast medium in the ultrasonography
BLECHA, Dalibor
Ultrasound method belongs to the most extended and easily available modern investigative diagnostic techniques. It is the step number one in the investigative diagnostic algorithm. The beginning of this method dates back to the early fifties of the twentieth century. With respect to the fact that the usage of ultrasound contrast agents and the development of an {\clqq}optimal`` contrast agent has not finished, I refer to some limitations and obstacles. Although this process is similar for all contrast agents in all fields of modern imaging methods. Implementing new findings and observations into a clinical practice is connected with lots of difficulties and obstacles that restrain their success. In the same way as the contrast agents found their application in various modern imaging techniques, the ultrasound contrast agents are also expected to find their place in the ultrasonography. This fact acknowledges my hypothesis and points at application of ultrasound method as the first choice.
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Software Package for Ultrasound Perfusion Imaging
Mézl, M. ; Jiřík, Radovan
In this work a Matlab-based software package for perfusion imaging is presented. It is run with a graphical user interface (GUI) and includes five main steps of perfusion analysis. There are applications for data import, image registration, tissue selection, perfusion analysis and visualization. This software has been used for analysis of abdominal ultrasound sequences. It is modular and each module can be easily modified for various methods as well as different image modalities for example magnetic resonance imaging.
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