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Segmentation of 3D image data utilising graph representation
Demel, Jan ; Walek, Petr (referee) ; Jan, Jiří (advisor)
This thesis deals with the application of graph theory in image segmentation. There are specifically presented method utilizing graph cuts and extensions of this method. In the first chapter thera are initially explained basics of graph theory that are essential for understanding of the presented method. It is described in the second chapter, including its extensions that use shape priors. In the third chapter there is presented solution which is used for vertebrae lesion segmentation in the CT data sets. Final function is implemented into the program but it can be used also separately. Success rate is described using sensitivity and specificity in the last chapter, there are also examples of results.
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Contour Shape Classification for Detection of Mis-Segmented bones in CT Data
Janovič, Tomáš ; Jan, Jiří (referee) ; Walek, Petr (advisor)
The thesis discusses the possibilities of using contour shape classification for detection of mis-segmented bones in computed tomography (CT) data. In the first part there are presented published methods and algorithms which deal with the segmentation of bone structures in CT data. Then segmentation of cortical bones is implemented by a simple thresholding with global threshold. The threshold is determined by the optimized fitting of a selected type probability distribution to the histogram. Subsequently, the thesis describes some important shape descriptors that can quantitatively describe the shapes of objects in the image. Further, the contour extraction is implemented and a suitable shape descriptor, cumulative angular function, is applied. Finally, the points which can potentially indicate mis-segmented bones are detected by using continuous wavelet transform. The proposed technique is tested on the real CT data.
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Movement correction in thoracic dynamic contrast CT data
Jakubíček, Roman ; Malínský, Miloš (referee) ; Walek, Petr (advisor)
This thesis deals with a nonrigid image registration for movement correction in thoracic dynamic contrast CT data. The deformation field is initialized by the analysis of disparities based on nonlinear matched filter, which defines local movement deformation. The values of control points are optimized by the Nelder-Mead method. The transformation model is based on a 4D (3D + time) free-form B-spline deformation for feature of movement distortion. The first part of the thesis briefly discusses the theory of image registration. Knowledge of this theory is necessary for understanding the remaining chapters, which describe the proposed method and its realization. The large part of this thesis is devoted to the geometrical image transformations, that is very important for the image registration. The thesis also describes a simplex method for function minimization. Three publicated methods of registration of medical 4D CT data are given. In the following chapter are individual parts of the purposed nonrigid registration including possible problems and their solution described.
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Measurements of Nanoparticles Infrared Absorption
Peprníčková, Anna ; Walek, Petr (referee) ; Sekora, Jiří (advisor)
This diploma thesis is focused on measurements of nanoparticles infrared absorption. In project is made literar research of sensors in part of IR area, principal design of detector controled by microcontroller for measurement absorption properties of solutions of nanoparticles and microparticles in IR area with diode detector and bank of optical filtres. According to this design of device microcontroller and display device was chosen. This work contains program design for microcontroler and display unit.
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Model of dynamic contrast CT data for verification of registration algorithms
Kupková, Karolína ; Harabiš, Vratislav (referee) ; Walek, Petr (advisor)
This work is focused on the description of the dynamic contrast-enhanced CT examination and its contribution in the pneumooncology. It includes a program for creating a two-dimensional model of the scan from the thorax and for the perfuse examination simulation using the time-density curve. Real CT data are simulated more authentic using rigid geometric transformations and noise. The model will be used for the validation of registration algorithms that is used to suppress the spatial deformation generated by patient motions during the long time examination.
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Affine registration of native and contrast-enhanced CT brain images
Chmelík, Jiří ; Mézl, Martin (referee) ; Walek, Petr (advisor)
This thesis is dealing with problem of brain images registration aquired by computed tomography. At the beginning is explanation of image geometrical transformation methods, notably affine transformation. Following part of text the is dealing with interpolation methods issues, calculation of similarity criterion and subsequent optimalization. All issues are handled especially for three-dimensional data. Second part of this work is practical sample of MatLab® program enviroment for registration of acquired frames by affine tranformation. In this program is algorithm for removement of stair-step artefact, under head pillow and patient’s desk, too. As an optimalization algorithm is used control random search (CRS) methode. Due to medical images type, which are distributed in DICOM format, is included process for their load and save at this work.
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Segmentation of the kidney from the renal perfusion MR image sequences
Jína, Miroslav ; Walek, Petr (referee) ; Malínský, Miloš (advisor)
This master’s thesis deals with kidney segmentation in perfusion magnetic resonance image sequences. Kidney segmentation is carry out by a few methods such as regionbased techniques, deformable models, specimen-based methods, edge-oriented methods etc. The universal algorithm for patient kidney segmentation still does not exist. Proposed method is an active contour Snake, which is created in programming environment MatLab. Final contours are quantitatively and visually compared to manual kidney segmentation.
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Pulsatile Magnetic Field Possibilities in Child Neurology
Walek, Petr ; Čížek, Martin (referee) ; Sekora, Jiří (advisor)
Project Pulsatile Magnetic Field Possibilities in Child Neurology in his forepart paies medical use of Pulsatile Magnetic Field. Summaries a therapeutic effects of field which is interacting with biotic issue and determines which of those effects are acceptable for treatment of Infantile Paralysis. Below it describes single Bio-Parametres of Pulsatile Magnetic Field and analyses reasons and effects of Infantile Paralysis. Below it describes single Bio-Parametres of Pulsatile Magnetic Field and anylyses reasons and effects of Infantile Paralysis. In second part is described a block diagram of magnetotherapeutic device for treatment of Infantile Paralysis. Described is principle of function of blocks. In third part is decribed circuit solving of magnetotherapieutc device and is desribed flowchart for microcontrollers.
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Registration of volume CT brain images by means of global affine 3D transform
Mikuláš, Karol ; Schwarz, Daniel (referee) ; Walek, Petr (advisor)
At present, the medical industry rapidly develops new imaging techniques and improves the imaging methods. Simultaneously also are developed new methods for processing data acquired by these methods. Especially in the past few years has become very used method of registration data, which leads to image transformations of the same scene so that the condition as possible. The work deals with the method of processing data that provides detailed information to individual structures, developments of individual structures over time, allows to simultaneously displayanatomical and physiological information or preprocessing data for further processing.
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Magnetotherapeutic device for Child Neurology
Walek, Petr ; Rozman, Jiří (referee) ; Sekora, Jiří (advisor)
Project Magnetotherapeutic device for Child Neurology in his forepart paies medical use of Pulsatile Magnetic Field. Summaries a therapeutic effects of field which is interacting with biotic issue and determines which of those effects are acceptable for treatment of Infantile Paralysis. Below it describes single Bio-Parametres of Pulsatile Magnetic Field and analyses reasons and effects of Infantile Paralysis. In second part is described a block diagram of magnetotherapeutic device for treatment of Infantile Paralysis. Described is principle of function of blocks. In third part is defined circuit solving of controlling, supervisory and generating part of magnetotherapeutic device. Function and wiring of components is described in detail. There is also created a Printed Circuit Board. Device is controlled by three microcontrollers, therefore there are described flowcharts and controlling programs for microcontrollers.
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