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Laboratory exercise for RTG imaging systems
Kuchař, Otakar ; Macíček, Ondřej (referee) ; Mézl, Martin (advisor)
The aim of this Bachelor thesis is to study the X-ray and computed tomography. The theoretical section explains the basic physical principles, elementary particle, atom and ionizing. The following parts of the thesis deal with topics from the origin and various types of X-ray, to interaction of X-ray with tissue and X-ray detection. For computed tomography the thesis also explains data collection, the reconstruction of image using simple back projection, filtered back projection and algebraic reconstruction. In the practical part are analysed several measurements which were taken in the X-ray chamber designed for educational purposes by Leybold. The topics solve the attenuation of X-rays depending on the type and thickness of the material and the spectrum of the X-ray radiation. In the field of computerized tomography solve tasks as the change of contrast, parameters of acquisition and methods for reconstruction. The work includes prepared sample solutions to a laboratory experiments.
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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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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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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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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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Výuka zobrazovacích systémů na Ústavu biomedicínského inženýrství FEKT VUT v Brně
Mézl, Martin ; Jiřík, Radovan
Příspěvek pojednává o výuce zobrazovacích systémů v rámci studijních programů v oblasti biomedicínského inženýrství na Ústavu biomedicínského inženýrství FEKT VUT v Brně. V rámci jednotlivých kapitol je představeno zařazení předmětů do studijních plánů, jejich obsah a formy výuky. Další kapitola představuje dostupné přístrojové vybavení na pracovišti a jejich užití v laboratorních úlohách. Samostatná podkapitola je věnována také softwarové podpoře výuky a exkurzím na brněnských pracovištích, se kterými spolupracujeme.
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CT and MR and their mutual use in diagnostics
KOCHWASSER, Jiří
This bachelor thesis deals with computed tomography and magnetic resonance imaging and their mutual use in diagnostics. Computed tomography and magnetic resonance imaging are an integral part of modern radiology and play an essential role in the accurate diagnosis of many diseases. In this field, quality and modern instrumentation and a professional approach of the medical staff performing the examinations are important. In the first, theoretical part, the physical principles of computed tomography and magnetic resonance imaging, their history and their characterictis are described in detail. The theoretical part is compiled from the specialised literature, both printed and published on the Internet and is prepared in the form of a search. This thesis aims to describe the detailed physical principles of both diagnostic methods, to analyse the applicability of these imaging methods in hospitals and to analyse the mutual use of computed tomography and magnetic resonance imaging. The thesis is designed as a comrehensive review concerning the use and operations of CT and MRI imaging methods. To meet the objectives and research questions, we used annual reports, from 2012 to 2021, on the instrumentation of healthcare facilities from the Institute of Health Information and Statics of the Czech Republic (IHIS), which are provided under the Ministry of Health´s Statistical Survey Programme. This objective was supported by the research question: What is the most common use of CT and MRI in the algorithm of medical imaging examinations?
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Implementation of a deep learning model for vertebral segmentation in CT data
Blažková, Lenka ; Chmelík, Jiří (referee) ; Nohel, Michal (advisor)
This bachelor’s thesis deals with the problem of vertebrae segmentation in CT data with the use of deep learning. Firstly, there is a theoretical review focused on the anatomy and the pathologies of the spine and the vertebrae, the CT systems, and the deep learning models for vertebrae segmentation in 3D data. The following section contains a more detailed description of the chosen model. The fifth section describes the implementation of the chosen model and the proposed modification, together with the results on the relevant database. In the end, the model with the modification is used on the clinical data provided by the supervisor and its evaluation is described.
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Noise reduction in high resolution computed tomography data
Tkadlecová, Markéta ; Chmelík,, Jiří (referee) ; Zikmund, Tomáš (advisor)
Vzhledem ke komplexnosti procesu akvizice dat výpočetní tomografie (CT) je šum v rentgenových snímcích nevyhnutelný a může vést ke zkreslení získané informace. Proto by měl být co nejvíce potlačen. Dosud se výzkum zaměřoval především na redukci šumu v CT datech u lékařských CT s nízkými dávkami, zatímco o šumu a jeho potlačení v CT datech s vysokým rozlišením je známo jen málo. Tato redukce může probíhat v oblasti rentgenových snímků, v průběhu tomografické rekonstrukce nebo v oblasti tomografických řezů. Tato práce se zabývá především redukcí šumu v rentgenových snímcích a tomografických řezech. Prvním krokem k nalezení komplexní metodiky je určení rozdělení a matematického modelu šumu přítomného v rentgenových snímcích. Tento model byl určen pomocí snímků bez přítomného vzorku, které byly pořízeny s různými expozičními časy. Pomocí stanoveného modelu byl simulován šum ve fantomovém datasetu. Vybrané algoritmy byly testovány na projekčních snímcích a tomografických řezech fantomu a porovnávány jak subjektivně, tak objektivně pomocí metrik kvality obrazu. Strategie s nejlepšími výsledky byly dále testovány na naměřených CT datech z CT systému Rigaku nano3DX s vysokým rozlišením a byly popsány jejich výhody, omezení a možnosti využití.
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Metal Artifacts Reduction in Dental CT Scans
Vágner, Dominik ; Juránková, Markéta (referee) ; Španěl, Michal (advisor)
Artifacts caused by the presence of metals in computed tomography scans impact their readability and can cause problems when making decisions for medical professionals. In recent years, deep learning-based methods have seen considerable success in solving this problem, compared to older hand-crafted solutions. In this work, two supervised neural network models (Autoencoder, U-net) are implemented, along with a better way to solve the problem of creating a synthetic dataset, as otherwise in this case it is naturally impossible to obtain. The results in evaluation metrics (PSNR, SSIM) achieved are on par with those of state-of-the-art solutions while reducing the need for prerequisites that are complicated to prepare. This generalized solution enables a broader and easier application without needing a specific controlled environment.
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