National Repository of Grey Literature 57 records found  beginprevious38 - 47next  jump to record: Search took 0.00 seconds. 
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.
Fusion and Analysis of Multidimensional Medical Image Data
Peter, Roman ; Flusser,, Jan (referee) ; Kozubek,, Michal (referee) ; Jan, Jiří (advisor)
Analýza medicínských obrazů je předmětem základního výzkumu již řadu let. Za tu dobu bylo v této oblasti publikováno mnoho výzkumných prací zabývajících se dílčími částmi jako je rekonstrukce obrazů, restaurace, segmentace, klasifikace, registrace (lícování) a fúze. Kromě obecného úvodu, pojednává tato disertační práce o dvou medicínsky orientovaných tématech, jež byla formulována ve spolupráci s Philips Netherland BV, divizí Philips Healthcare. První téma je zaměřeno na oblast zpracování obrazů subtrakční angiografie dolních končetin člověka získaných pomocí výpočetní X-Ray tomografie (CT). Subtrakční angiografie je obvykle využívaná při podezření na periferní cévní onemocnění (PAOD) nebo při akutním poškození dolních končetin jako jsou fraktury apod. Současné komerční metody nejsou dostatečně spolehlivé už v předzpracování, jako je například odstranění pacientského stolu, pokrývky, dlahy, apod. Spolehlivost a přesnost identifikace cév v subtrahovaných datech vedoucích v blízkosti kostí je v důsledku Partial Volume artefaktu rovněž nízká. Automatické odstranění kalcifikací nebo detekce malých cév doplňujících nezbytnou informaci o náhradním zásobení dolních končetin krví v případě přerušení hlavních zásobujících cév v současné době rovněž nesplňují kritéria pro plně automatické zpracování. Proto hlavním cílem týkající se tohoto tématu bylo vyvinout automatický systém, který by mohl současné nedostatky v CTSA vyšetření odstranit. Druhé téma je orientováno na identifikaci patologických změn na páteři člověka v CT obrazech se zaměřením na osteolytické a osteoblastické léze u jednotlivých obratlů. Tyto změny obvykle nastávají v důsledků postižení metastazujícím procesem rakovinového onemocnění. Pro detekci patologických změn je pak potřeba identifikace a segmentace jednotlivých obratlů. Přesnost analýzy jednotlivých lézí však závisí rovněž na správné identifikaci těla a zadních segmentů u jednotlivých obratlů a na segmentaci trabekulárního centra obratlů, tj. odstranění kortikální kosti. Během léčby mohou být pacienti skenováni vícekrát, obvykle s několika-mesíčním odstupem. Hodnocení případného vývoje již detekovaných patologických změn pak logicky vychází ze správné detekce patologií v jednotlivých obratlech korespondujících si v jednotlivých akvizicích. Jelikož jsou příslušné obratle v jednotlivých akvizicích obvykle na různé pozici, jejich fúze, vedoucí k analýze časového vývoje detekovaných patologií, je komplikovaná. Požadovaným výsledkem v tomto tématu je vytvoření komplexního systému pro detekci patologických změn v páteři, především osteoblastických a osteolytických lézí. Takový systém tedy musí umožnovat jak segmentaci jednotlivých obratlů, jejich automatické rozdělení na hlavní části a odstranění kortikální kosti, tak také detekci patologických změn a jejich hodnocení. Ačkoliv je tato disertační práce v obou výše zmíněných tématech primárně zaměřena na experimentální část zpracování medicínských obrazů, zabývá se všemi nezbytnými kroky, jako je předzpracování, registrace, dodatečné zpracování a hodnocení výsledků, vedoucími k možné aplikovatelnosti obou systému v klinické praxi. Jelikož oba systémy byly řešeny v rámci týmové spolupráce jako celek, u obou témat jsou pro některé konkrétní kroky uvedeny odkazy na doktorskou práci Miloše Malínského.
Segmentation of 3D image data based on deformable models
Klásek, Pavel ; Peter, Roman (referee) ; Jan, Jiří (advisor)
This document deals with the pre-processing and the segmentation of human vertebrae from computed tomography 3D image data. It describes image registration and segmentation methods concretely and commonly used in image data processing during the automated spine canal localization process and the localization of each vertebrae centroid. The 3D deformable model development is described in the work together with the introduction to the previous state of art and the progress of vertebrae segmentation using 3D deformable models registration. This work presents the evaluation of the accuracy and the reliability from the segmentation and localization results.
The use of computed tomography for control homogeneity of steel fiber-concrete structures
Hobst, Leonard ; Bílek, Petr ; Zikmund, Tomáš
Inappropriate processing of and deposition the mixture during the manufacturing process fiber-concrete structures, the fibers are often unevenly distributed. May experience a grouping of wires, which reduces the overall homogeneity and the quality of steel fiberconcrete structures. The paper deals with the development for monitoring the distribution of fibers in hardened steel fiber-concrete structures using industrial computed tomography.
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.
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).
The role of imaging techniques in creation of computational models in biomechanics.
Prášilová, Eva ; Valášek, Jiří (referee) ; Marcián, Petr (advisor)
The first part of the bachelor´s thesis is dealt with the processing history of imaging techniques and their indications in a clinical practice. From point of view of the computer modeling, the computer tomography plays an important role in biomechanics. The second part of this treatment describes the scan processing of sections of two human mandible obtained from computer CT and micro-CT tomography. As a non-invasive way procedure can be characterized the image processing techniques, which analyze a bone density and BVF. The manual segmentation was applied in this analysis provided in ROI analysis software. There are shown the graphs of the bone densities of segments of two human mandibles depending on the specimen length and also there are compared the results of the measurements received from the CT and micro-CT tomography. Then follow the results illustrating the correlation of the relations and recalculations, which can be used as the determination tool of the mechanical properties of bone tissue. Finally there are described the computer models created in ANSYS focused on the different bone density analysis and stress strain analysis.
The specifics of CT and MR examination in children
NOSKOVÁ, Kateřina
The bachelor's work deals with specifics of examining children by mean of computed tomography (CT) and magnetic resonance imaging (MRI). Radiological imaging methods CT and MRI are irreplaceable for exact diagnostics of all kinds of diseases and form an integral part of modern paediatric radiology. What is important is not only technological equipment of high quality and specific procedures, but also a professional approach of the medical staff that carry out an intervention. The goal of the work is the provision of basic information about CT and MRI methods, the accent being on child patients, and the description of the course of the above-mentioned examinations in children. Another goal is to analyze specifics of individual examinations. The staff should act professionally as working with children requires a fair amount of patience and understanding. The capability to explain, as easily and effectively as possible, to the parents and the child how the examination will go on is no less important. The examination must be carried out as quickly as possible and the chosen examining method must bring a result of sufficient quality. While being examined, the patient is required to stay at rest in bed, which is a frequent problem in little patients. The theoretical part is divided into a few chapters. Individual chapters describe individual imaging methods and their advantages and disadvantages. Furthermore, there is an overview of contrast agents there, their classification and possible undesirable effects. A chapter on paediatric anaesthesiology is not missing either the knowledge of this area is often very important, especially when examining children under 5 years of age, claustrophobic patients or very restive children. The aim of the practical part of the work was to evaluate the information the parents have on the examination that was indicated to their child (CT/MRI). To that end, a questionnaire was developed, which was available at the Clinic of Paediatrics of the Motol Teaching Hospital (Clinic of Imaging Methods) and in the Brno Teaching Hospital (Clinic of Paediatric Radiology) and contained 25 questions in all. Answers to the questions could have been marked with a cross, elsewhere free answers were possible. Furthermore, data on the number of children examined by means of CT and MRI methods at clinics of paediatrics existing with hospitals having special paediatric radiodiagnostic departments (Motol Teaching Hospital Clinic of Imaging Methods and Brno Teaching Hospital Clinic of Paediatric Radiology) between 2010 and June 2015 was analysed. The data analysed was divided into a few age categories, as per specific needs of the child. The analysis of the data should have helped answer research questions to what extent the parents were informed of the course of the examination of their child and whether the number of children examined by means of CT and MRI methods was increasing. In order to answer the research questions, data from the clinics of paediatrics having special paediatric radiological departments (Motol Teaching Hospital Clinic of Imaging Methods and Brno Teaching Hospital Clinic of Paediatric Radiology) was utilized, as well as the completed questionnaires. The chapter "Results" shows, with the help of graphs, answers to the questions from the questionnaire investigation and the data acquired in the Motol Teaching Hospital (Clinic of Imaging Methods) and the Brno Teaching Hospital (Clinic of Paediatric Radiology). In the chapter "Discussion", the results of the questionnaire investigation and the data acquired are evaluated. The work and its results can be utilized by other radiodiagnostic departments, or they can serve as supplementary material or material of advice for parents and students.
Comparison of injection molding process for two types of injection molding machines
VALTA, Arnošt
Annotation: The theoretical part deals with the comparison of two types of injection molding machines, especially comparison of the injection units. In thesis is described the basic structure and differences in various parts of the drive unit of injection units and measurement of individual injection parameters. In short is described the injection molding process with regard to parts manufactured at Robert Bosch, spol. s r. o. The aim of the thesis is to recommend the type of injection molding machine with respect to the production components and according to the needs of the production department. The practical part is focused on the production of plastic samples of flanges and pots which are parts of the fuel pump module. Both products were made on both type of injection molding machines, such as the hybrid and also the hydraulic injection molding machine. Dimensional and CT analysis evaluated the qualitative aspect of the products. The whole thesis contents pictures for a better understanding process of the injection molding.
Examination of the urogenital system Hospital Department of Radiology Jablonec nad Nisou p.o.
MENŠÍKOVÁ, Věra
The bachelor thesis named Examination of the urogenital system Radiodiagnostics Hospital Jablonec nad Nisou c. o. deals with methods of examination of the genitourinary system and creates a list and description of each method, using at these examinations. A radiology assistant is a non medical healthcare expert who uses their theoretical and practical knowledge gained during their university study in the fields of radiodiagnostics, radiotherapy and nuclear medicine. Radiology assistants are erroneously perceived both by other medical personnel and by lay public as technical workers. However, they are also medics who must be able to manipulate with highly sophisticated equipment but also provide medical care to the patients in full scale. As regards radiodiagnostics, the radiology assistants' task is to carry out the examination itself and obtain graphic documentation thereof. Radiology assistants ensure examination and handling of the equipment and they assist the doctor radiologist during more exacting intervention procedures. Radiology assistants' job is highly erudite and people working with ionising radiation must strictly abide by the laws and regulations stipulating strict rules and requirements which each radiology assistant must meet when they want to perform this activity. Radiology assistants' approach must help reduce the radiation burden of the population. It is logical, that the technological development goes hand in hand with higher examination yield and the ALARA principle is generally adhered to and applied in all examinations. If we strive to decrease the radiation dose, it is necessary to use an optimum amount of contrast agents. At the beginning of the thesis, there is a detailed description of urogenital system anatomy and physiology whose knowledge is a must when one wants to work in this field. Imaging methods described in the thesis range from the simplest ones to the most complex ones, both as regards the examination time and pursuant to specifications associated with individual examination types. The examination should be carried out from the least invasive examination procedures to the most complex ones. The methodics is based on gathering, study and subsequent analysis of the obtained data. Data from years 2009 2013 obtained at the radiodiagnostic ward of Nemocnice Jablonec nad Nisou p.o. hospital was gathered for this purpose. Investigations are divided into a number of men and women undergoing these tests. Investigative methods are compared, and evaluated that prevail, and from which they are abandoned prevail and which are being gradually abandoned. For the purpose of my thesi. The gathered data was processed into tables and synoptic graphs. Information from expert books, articles and verified Internet sources were used in the bachelor thesis. Results of my study confirmed the research question, the number of patients who undergo examinations of the urogenital system Radiodiagnostics Hospital Jablonec nad Nisou after rising. Preference tests are noninvasive and greater diagnostic yield. It is also found, however, that certain examination still have their place and are being replaced by another method. This example of hysterosalpingography. The aim of the thesis was to create an overview and description of individual radiodiagnostic methods in uropoetic system examinations and analysis of data from radio diagnostic department Hospital Jablonec nad Nisou regarding the examination of the urogenital system. The number of examinations in the radiodiagnostic ward is rising and the demands placed on a radiodiagnostic assistant are also continuously increasing from both physical and mental point of view. Radiology assistants are obliged to improve their knowledge and skills actively by means of training sessions and self study.

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