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Algorithms for the image reconstruction from projections
Zemek, Marek ; Chmelík, Jiří (referee) ; Mézl, Martin (advisor)
This work focuses on the task of reconstructing an image from its projections, particularly in relation to the CT medical imaging modality, and the evaluation of the quality of this reconstruction using various types of algorithms. First, the theory behind contemporary reconstruction algorithms is discussed. Next, this paper deals with the implementation of several simple methods of image reconstruction in Matlab, their application on simulated as well as real data, and subsequent evaluation in terms of reconstruction quality and computational complexity.
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Anatomy based landmark detection in brain CT scans
Krajčiová, Alexandra ; Harabiš, Vratislav (referee) ; Jakubíček, Roman (advisor)
Manual detection of anatomical landmarks from head CT (Computed Tomography) scans is time-consuming task prone to observer errors. In addition, the accuracy of the detection correlates with image quality. The aim of this work is to create an algorithm that will perform automatic detection of anatomical landmarks. These landmarks can be later used to form radiological lines, which finds its application in CT scanning. SVM (Support Vector Machines) and HOG (Histograms of Oriented Gradients) features was chosen for anatomical landmark detection. The achieved results, possibilities of further progress and improvement of detection are summarized in the conclusion.
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The Three-Dimensional Digital Imaging Methods for X-ray Computed Tomography and Digital Holographic Microscopy
Kvasnica, Lukáš ; Číp, Ondřej (referee) ; Štarha, Pavel (referee) ; Chmelík, Radim (advisor)
This dissertation thesis deals with the methods for processing image data in X-ray microtomography and digital holographic microscopy. The work aims to achieve significant acceleration of algorithms for tomographic reconstruction and image reconstruction in holographic microscopy by means of optimization and the use of massively parallel GPU. In the field of microtomography, the new GPU (graphic processing unit) accelerated implementations of filtered back projection and back projection filtration of derived data are presented. Another presented algorithm is the orientation normalization technique and evaluation of 3D tomographic data. In the part related to holographic microscopy, the individual steps of the complete image processing procedure are described. This part introduces the new orignal technique of phase unwrapping and correction of image phase damaged by the occurrence of optical vortices in the wrapped image phase. The implementation of the methods for the compensation of the phase deformation and for tracking of cells is then described. In conclusion, there is briefly introduced the Q-PHASE software, which is the complete bundle of all the algorithms necessary for the holographic microscope control, and holographic image processing.
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Image segmentation of spinal disc in medical imaging
Meloun, Jan ; Nemček, Jakub (referee) ; Mézl, Martin (advisor)
The thesis is focused on the segmentation of the intervertebral disc in the image data.The introduction deals with the issue of the spine, the herniation of the intervertebraldisc. It also deals with imaging modalities, especially computed tomography and mag-netic resonance imaging. The practical part describes the image data segmentation andthe implementation of three of the published segmentation methods.
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X-ray computed tomography analysis of mouse embryonic heart
Dobrovodská, Daniela ; Oberta, Peter (referee) ; Zikmund, Tomáš (advisor)
Rentgenová počítačová tomografie je univerzální technika umožňující nedestruktivní trojrozměrné (3D) zobrazování. Je široce používána v průmyslu pro metrologii a charakterizaci materiálů. V poslední době našla svůj význam také v biologii a vývojové vědě, kde 3D rekonstruovaná data poskytují komplexnější informace o vzorku než konvenční 2D zobrazovací metody. Kromě toho může vytvářet vysoce kvalitní snímky různých biologických vzorků. Překážkou při zobrazování biologických vzorků může být velmi podobný koeficient útlumu měkkých tkání, a proto je nutné použít barvení chemickou látkou. Tato práce si klade za cíl pomocí mikropočítačové tomografie vizualizovat a kvalitativně vyhodnotit srdce embryonálních myší E17.5 a představit nejlepší barvící protokol. Dále byla zavedena metodika pro zvýraznění rozdílů mezi myší divokého typu a mutantem. Rigaku nano 3DX byl použit pro experimenty s mezi-komorovou přepážkou myšího srdce a po nastavení specifických parametrů zařízení byl použit algoritmus pro zvýraznění fáze. Nakonec byla provedena validace $\mu$ CT dat se snímkami z konfokálního mikroskopu.
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Image segmentation of spinal disc in medical imaging
Meloun, Jan ; Nemček, Jakub (referee) ; Mézl, Martin (advisor)
This thesis is focused on segmentation of intervertebral discs in images from two medical imaging modalities - computed tomography (CT) and magnetic resonance imaging (MRI). Theoretical introduction of the thesis describes intervertebral disc herniation and relevant imaging modalities. It also includes description of basic and advanced segmentation methods. For practical part of the thesis, three different segmentation teqniques (one for CT data and two for MRI images) have been chosen, implemented and applied on images acquired at Radiodiagnostic department of Havlíčkův Brod hospital. The segmentation quality has been assessed quantitatively for individual methods by comparing the segmentation results to manually created reference segmentation of intervertebral discs.
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Possibilities of the object surface determination in tomographic data set
Kalasová, Dominika ; Novotný, Jan (referee) ; Zikmund, Tomáš (advisor)
This work studies the possibilities for determining surfaces of objects in tomographic data. This procedure is important for post-processing - object visualization, coordinate measuring, export to STL file format etc., and it is complicated due to tomographic artifacts, porosity of material, material inhomogenities, and low-quality data. The possibilities of the surface determination in VGStudio MAX 2.2 software are described and demonstrated on steel fiber-reinforced concrete sample.
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Vertex and Pixel Shaders OpenGL Visualisation of Medical 3D Image Data
Vaďura, Jiří ; Španěl, Michal (referee) ; Kršek, Přemysl (advisor)
This thesis deals with accelerated 3D rendering of medical data, e.g. computed tomography, using a graphics processor and OpenGL library. Raw data slices are send to graphic memory and rendered by a ray-casting algorithm. The goal of this project is high quality visual output and full user interaction at the same time. Multiple rendering modes are avaiable to the user: MIP, X-Ray simulation and realistic shading.
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Construction of motorized filter changer for tomographic system Rigaku Nano3DX
Maleček, Lukáš ; Nožičková,, Dominika (referee) ; Zikmund, Tomáš (advisor)
X-ray computed tomography is a technique that finds widespread application nowadays. The initial use of this technique was mainly in medical diagnostics. The achievable accuracy of this technique has been progressively improved so much that today the computed tomography finds applications even in the field of industry. It is a non-destructive method of three-dimensional imaging of the internal structures of the examined objects. The quality of the resulting CT data is influenced by several factors. One of these factors is the property of X-rays, which we use for measurements. We are able to partially alter the properties of X-rays and thus obtain higher quality CT data, without the occurrence of some tomographic artifacts. The main way how we can change the properties of the generated X-rays is called additional filtration. This work deals with the study of X-ray spectra, based on which X-ray filters are optimized, to achieve the most efficient filtration. The main aim of this bachelor thesis is also the construction and production of a motorized changer of these filters, which should cause the speeding up the process of setting the whole CT measurement and allow the development of new computed tomography techniques.
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Modern trends in radiographic procedures and methods in defectoscopy
Skřivánková, Vendula ; Vlašic, František (referee) ; Juliš, Martin (advisor)
Presented thesis deals with modern trends and techniques in radiographic methods of crack detection which are recently used in engineering practice. In the first part, conventional (analogue) radiography principles based on creating a visible image of tested object to radiographic film are discussed. The next part is aimed to the digital radiography and radioscopy. To digitize existing X-ray film images, application of storage phosphor plates (CR), flat panels (DR) and computed tomography (CT).
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