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The role of radiographer during MR angiography
ZBĚHLÍKOVÁ, Pavla
The role of radiographer during MR angiography Objectives: The thesis and the tutorial CD provide information on the magnetic resonance angiography {--} MRA. Due to upgraded hardware and software and the non-invasive character of the examination the method is currently the most common form of the imaging of flowing blood in vessels. It is essential for a radiographer to acquire comprehensive knowledge of the basic principles and techniques of MRA. The objective of my thesis was to find out if the method can be used not only for a high-quality imaging of the arteries but also for subsequent therapeutical procedures. Methodology: The research was conducted with 106 patients (66 men and 40 women) whose lower limb arteries had been tested by MRA between 1 January and 31 December 2007 at the Multiscan RC Pardubice. I determined the number of patients who had undergone a therapeutical procedure after the MRA test (operations on arteries, percutaneous transluminal angioplastics) and assessed to what degree the MRA examination had been sufficient for the surgery. Results: In 91 % out of 46 patients indicated for therapeutical procedures the results obtained by MRA enabled other treatment or a surgical procedure. Only in 9 % patients the results obtained by MRA were not sufficient for other medical treatment and suplementary examinations such as the diagnostic digital subtraction angiography were necessary. Conclusions: MRA is a non-invasive medical diagnostic technique to visualize the blood in vessels which provide satisfactory accuracy without exposing the patient to any ionizing radiation. The results are used for other treatments. Radiographers who master the MRA techniques avoid mistakes that might devalue the test. Key words: digital subtraction angiography, magnetic resonance angiography, magnetic resonance imaging, percutaneous transluminal angioplastics, radiographer {--} radiologic technologist.
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CYCLIC PLASTICITY AND DISLOCATION SUBSTRUCTURE OF ferritic STAINLESS STEEL
Petrenec, Martin ; Polák, Jaroslav
The cyclic plastic response of polycrystalline ferritic stainless steel with b.c.c. structure is analysed in terms of the general statistical theory of the hysteresis loop and cycled in the magnetic field. Simultaneously, the internal dislocation substructure developed in the material during cyclic straining is studied using transmission electron microscopy and Kikuchi lines. The inhomogeneous distribution of dislocations into the persistent slip bands can be correlated with the localization of the cyclic plastic strain. The analysis of the loop shape by plotting the first and the second derivative of the half-loop allows determining the effective stress and the probability density function of the critical internal stresses. Extra peak of the second derivative of the half-loop was explained by the inverse magneto-elastic effect.
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The influence of geomagnetism on the behavior of dogs
PLACHOVÁ, Denisa
The aim of this bachelor thesis was to evaluate the influence of geomagnetism on the dog. The theoretical part contains information from technical literature and articles concerning the ability of different species (from primitive organisms to large mammals) perceive the Earth's magnetic field and use it for their orientation and navigation. The practical part deals with own observation of the dog of the breed called pug, when was watched the spontaneous directional orientation of the dog during feeding, resting and excreting. Monitoring was carried out in a few months and the only tool, which was used was the compass, by which was recorded the direction in which the head of the dog was oriented during the individual activities. All measured values were entered into the tables created in Microsoft Excel spreadsheet and after that were statistically evaluated. From the evaluated data emerged that the dog during each of the monitored activity exhibited some directional preference. When feeding the dog preferred axis NW/SE, when resting S/SE direction and during excretion preferred axis NW/SE.
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The comparison of imaging methods in diagnosis of renal artery diseases
PAVLIŠOVÁ, Ivana
The present brings much information on development and course of various health disorders, including those of renal arteries. These disorders may be in the majority of cases both the cause and effect of serious diseases. The disorders of renal arteries represent risks to the patients undergoing their diagnostics. With development of technical and testing procedures, and with acquiring of new experience, the new, ionizing-radiation-free methods become more available. My bachelor's thesis maps the available methods carried out at the Department of Imaging Methods in the Motol University Hospital. The thesis describes the methods applying imaging by ionizing radiation (digital substraction angiography and computer tomography), as well as the methods using other physical principles for imaging, i.e. magnetic resonance and ultrasonic diagnostics. The thesis explores the algorithm of testing according to the indications and contraindications to the specific examination, and according to the age and sex of the patient. I have pointed out both advantages and disadvantages of the individual methods that might influence the expected results of examination. I concentrated on the contemporary situation of magnetic resonance in the diagnostics of renal arteries, which is gradually replacing the digital substraction angiography. The hypothesis consists of the role of the magnetic resonance in diagnostics of renal arteries, which is minimally limited by contraindications. The description of diagnostic procedures is based on medical literature and specialized sources. The information on the patients' examination has been drawn from the UNIS hospital information system in the Motol University Hospital. The conclusions shall serve as the basis for the internal methodical approach in diagnostics of the disorders of renal arteries.
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Vliv magnetické susceptibility na T1 relaxace 129Xe.
Bartušek, Karel ; Rychnovský, Jan
Every substance has its own susceptibility, which can affect homogenous magnetic field in magnetic resonance measuring. Local homogenous magnetic field deformation reduces T1 and T2 relaxation times of measured materials. By the laboratory glasses magnetic susceptibilities measurement, we obtained theirs walls influence to thermally polarized 129Xe T1 relaxation times.
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SMV-2013-07: Development and validation of a body of methods for imaging and analysis of an animal model of schizophrenia by 9.4-Tesla magnetic resonance, and analysis of a sample provided
Starčuk jr., Zenon ; Dražanová, Eva ; Jiřík, Radovan ; Rychnovský, Jan ; Starčuková, Jana ; Kořínek, Radim
A contract-based research with a specified mouse model of schizophrenia was carried out, examining the possibility of imaging relevant parameters of the structure and function of organs specified by the client. The options were assessed with respect to client's needs, suitable imaging methodology was identified and developed, animal experiment protocols were prepared and validated, and the proposed methodology was applied to a series of 60 animals according to valid animal use protocols. Original and statistically evaluated data were provided to the client.
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Studies of structural and magnetic properties of iron nanowires from first principles
Zelený, Martin ; Šob, Mojmír ; Hafner, J.
In this work we study the structure and stability of iron ultrathin free-standing nanowires by first-principles density functional approach. For total energy calculations, we use the Vienna ab initio Simulation Package (VASP) in the projector augmented-wave (PAW) representation. The evolution of electronic structure and magnetism of iron chains as a function of compression and stretch is investigated. The forming of different types of structures is analyzed: simple linear chain, dimerized chain, ideal two-dimensional (2D) zig-zag structure relaxed in x and y directions, fully relaxed 2D structure, and three-dimensional (3D) structure with tetrahedral arrangements. It turns out that the structure of iron nanowires and types of interatomic bonds are strongly dependent on their stretch or compression.
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