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Reconstruction of the face using skull:analysis of CT images of the head of adult Czech population
Drgáčová, Anna ; Velemínská, Jana (advisor) ; Brůžek, Jaroslav (referee)
AJ Knowledge of the soft facial tissues is the basis of any craniofacial reconstruction. It is of a great importance mainly for forensic practice, but it plays an important role in other fields, for example aesthetic surgery. Defining the thickness of facial tissues for different sexes, age and ethnic groups is an important aspect of forensic anthropology. The thesis specialises in finding out the thickness of soft facial tissues in modern czech population, it takes into consideration the sex, age and assymetry. The main source of information are the CT scans of the heads of 46 adult women and 56 adult men of czech nationality ranging between ages 21 to 83. 80 landmarks are defined in each scan, therefore 40 linear measurements between corresponding points have been evaluated. Data were analysed using the PCA, Hotelling test, linear discrimination analysis, Kolmogorov-Smirnov test, MANOVA, Kruskal-Wallis test and Wilcoxon paired test. Retrieved thicknesses of soft tissues will serve as the standards for the current czech population. Sexual dimorphism has been proven regarding the whole face, as well as both upper and lower parts of the face. The success of classification on the upper part of the face decresases significantly. Aging has been proven to have strong effect on the thickness of soft...
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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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Quality control of injection molded plastics using X-ray computer tomography
Figar, Erik ; Šrámek, Jan (referee) ; Jankových, Róbert (advisor)
This Master‘s thesis deals with an aplication of computed tomography as the technology for quality control check of the plastic parts made by the injection molding process. The analyses were performed on two different types of plastic parts. These parts were delivered by two companies and they included the drawing documentation and CAD models. These plastic parts were analyzed according to their qualitative requirements. The analyses included evaluation of the geometric tolerances and porosity analysis with numerical and graphical evaluation. The new module for tool correction ,which is part of VGStudio Max, was tested on parts that were not in accordance with the required tolerances. Afterwards the new corrected geometries were exported. At the end of this Master’s thesis the porosity comparison was assessed between two different voxel resolution CT data. This comparison shows the complexity of this phenomenon and the importance of voxel resolution settings.
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Development and use of non-destructive testing methods from the point of view of forensic engineering
Bílek, Petr ; Vala, Jiří (referee) ; Vodička, Jan (referee) ; Hobst, Leonard (advisor)
Concretes reinforced by, using distributed steel reinforcements (fibres) are known as fibre-concrete. In case of disturbances or accidents of concrete structures reinforced with wires, it is necessary to carefully examine the actual implementation of dispersed reinforcement. Fibre concretes belong to modern building materials whose possible applications have not been fully utilized so far. Have been mainly used for floor structures loaded with factory halls and warehouses. Recently, thanks to well-known physical and mechanical properties of fibre-concrete, there were numerous attempts of designers, and namely investors, to utilize this kind of materials for support structures either. Favorable properties of wire-concrete can be utilized if there is a necessity to increase the resistance of concrete to stresses exceeding its strength, cyclic stress or impact stress. Daily practice shows to prove that the applications of fibre-concrete in such structures lead to the economic success. Necessary condition for successful application of steel fiber reinforced concrete in constructions however consists in its uniform dispersion, a homogeneous distribution of the wires throughout the volume of the structure. In case of inappropriate processing and deposition of the mixture during the manufacturing process fiber-concrete structures, the fibers are often unevenly distributed. Wires itself represent unfavourably shaped mixture components and they are extremely deteriorating its workability. A grouping of wires may be encountered as well, which reduces the overall homogeneity and the quality of steel fiber-concrete structures. If the homogeneity of fibre-concrete is not kept, the material possess different properties in various parts of the structure (for example, tensile strength), which can lead to defects in the structure (generation and development of cracks). The relevant lower reliability of the structure which is caused by unequal distribution of fibres (wires) in concrete volume can lead to damage of the property as well as the safety and the human lives can be jeopardized. Hence it is necessary to secure the effective control of the fibre-concrete homogeneity in ready support fibre-concrete structures. Contemporary homogeneity control is still ongoing on fresh blends, but if the fibre-concrete hardened and is a part of the construction, no known reliable methods are currently in available to test the homogeneity of the fibre-concrete on the structure without its destruction. The methods developed to control the concentration of wires in wire-concrete structures are based mostly on magnetic or electromagnetic properties of wires. The thesis deals with the development of the magnetic method in situ using permanent magnets for monitoring the distribution of fibers in hardened steel fiber-concrete structures. The test principle is based on measurements of the changes in magnetic field strength of permanent magnets which are induced by a change in wire distribution in steel fibre-concrete structure. Test is characterized as a so called local- failure- test using a small diameter core drill. In this sense it is a semi-destructive method.
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Segmentation of soft tissues in facial part of mouse embryos from X-ray computed microtomography data
Janštová, Michaela ; Harabiš, Vratislav (referee) ; Chmelík, Jiří (advisor)
This diploma thesis deals with a segmentation of soft tissues in facial part of mouse embryos in Matlab. Segmentation of soft tissues of mouse embryos was not fully automated and every case needs a specific solution. Solving parts of this issues can provide valuable data for evolutionary biologists. Issues about staining and segmentation techniques are described. On the basis of accessible literature otsu thresholding, region growing, k-means clustering and segmentation with atlas were tested. In the end of this paper are those methods tested and evaluated on 3D microtomography data.
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Research study of mechanical properties of cranial tissue
Wojtek, Lukáš ; Valášek, Jiří (referee) ; Marcián, Petr (advisor)
This bachelor thesis deals with the problematics of determining mechanical properties of cranial bone tissue. In this thesis a search study associated with an experimental determination of mechanical properties of bone tissues is executed. A brief history and progress of imaging methods and their importance of computation modelling are introduced. There are descriptions of histomorfometric parameters describing a structure of bone tissue at the micro level, ways of their computation and their impact on mechanical properties of bone tissue. Practical part of the thesis is focused on processing micro-CT images of cranial bone as well as analysing histomorfometric parameters (BV/TV, TbTh, TbSp) and subsequently stress strain analysis of selected sections of cranial bone tissue. Resulting Young´s modulus of elasticity of bone tissue [MPa] are compared with results from experiments from literature.
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Hybrid renderer
Goliaš, Matúš ; Pelikán, Josef (advisor) ; Horáček, Jan (referee)
Title: Hybrid renderer Author: Matúš Goliaš Department: Department of Software and Computer Science Education Supervisor: RNDr. Josef Pelikán, KSVI Abstract: In medical applications, there are often used both volume data and objects defined by their surface. However, rendering these two types of data together is rather dif- ficult. This thesis provides the description of ray marching algorithm for volume rendering. We base the algorithm on the emission-absorption model of light trans- fer through a gaseous material. Moreover, we discuss the problems of adding meshes to the volume with respect to the algorithm. Next, we propose an ex- tension of ray marching which takes all meshes into account and renders them with the volume correctly. In addition, we compare the individual approaches for solving steps of the algorithm. Finally, we implement our solution in an ap- plication for volume viewing. We develop this renderer using OpenGL and we discuss our options of implementation. Furthermore, we extend our application by allowing the camera inside the volume, clipping the scene and interactive edit- ing of transfer functions which define the colour representation of volume data. Subsequently, we describe every feature and discuss its possible implementations. Keywords: volume data, ray marching, translucent...
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Creating a computational model of the human vocal tract
Freiwald, Michal ; Hájek, Petr (referee) ; Švancara, Pavel (advisor)
The research part of this bachelor’s thesis consists of a brief introduction to the human respiratory system and its subsidiary vocal subsystem along with a summary of basic phonation theories, voice disorders and published computational models of the human vocal tract. The experimental part engages in the making of the computational model itself, set to pronunciation of the vowel /a:/ in a woman vocal tract, on which, using finite element method, some of the basic acoustic analyses are performed, such as modal analysis or harmonic analysis. Calculated formants correspond with the values published in literature. Several different methods were analyzed while computing harmonic response. The most complex and the most time-consuming method, using infinite elements, also proved to be the most precise one. Thesis gives a decent comparison of the precision and complexity between the used methods.
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The Potential of computed tomography in the research of vertebrates
Piskáčková, Anna ; Frýdlová, Petra (advisor) ; Minařík, Martin (referee)
This thesis explores and classifies the capacities of computed tomography (CT) and mainly microcomputed tomography (micro-CT) in vertebrate research. The thesis pursues the application of the method in imaging the particular structures, tries to gain a knowledge as wide as possible about the studied tissues of vertebrates and about the resolution achieved with micro-CT and evaluates the optimal employment of this method. The aim of this thesis is to propose particular structures ideal for employment of this progressive method with high resolution in morphological, ecomorphological and phylogenetical context of research in vertebrate zoology. At present computed tomography is commonly used diagnostic method, which is employed not only in the medical and veterinary practice but also in biological research. The advantage of computed tomography is it's speed and the fact that it isn't invasive. CT and micro-CT can display mineralized tissues but also soft tissues with used of contrast agents. By micro-CT we create accurate three-dimensional projections of little structures. This can be helpful for example in research of spatially complex skulls and skeletons of even very small vertebrates. At first the thesis tries to map the principles of CT and mikro-CT, the history and the potential of the technique...
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Medical image registration
Lacmanová, Zdeňka ; Soukup, Jindřich (advisor) ; Hnětynková, Iveta (referee)
This thesis deals with the registration of images, which differ only in the shift and rotation, taken from CT angiography. The term of registration and transformation between the images are explained here. Three methods are used for registration. The first method is based on Fourier transform and it is called the phase correlation. The other two methods use the measured data by phase correlation and then the data is processed using the least squares method or singular value decomposition. There is given detailed theoretical foundation, the methods are mathematically derived and then implemented and tested in Matlab. Powered by TCPDF (www.tcpdf.org)
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