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The Segmentation of Ultrasound Images for Artery Wall Detection and Intima-Media Thickness Measurement
Beneš, Radek ; Chromý,, Erik (referee) ; Dostál, Otto (referee) ; Říha, Kamil (advisor)
The thesis focuses on the measurement of intima media thickness, which seems to be a significant marker of the risk of cardiovascular events. Intima media thickness is measured in ultrasound image displaying the common carotid artery in its longitudinal section. In the longitudinal section the intima and media layers are visible. Thesis is discussing both technical and medical background and summarizes state of the art in this field. The main part of the thesis describes the novel automatic system for measurement of intima media thickness. Proposed system includes also robust method for artery localization and therefore is able to process raw B-mode data from ultrasound station without any initialization or manual preprocessing.
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Stress-strain analysis of artificial vascular grafts
Chomič, Dimitrij ; Návrat, Tomáš (referee) ; Burša, Jiří (advisor)
This thesis deals with the computational solution of stress-strain states in the vicinity of the connection (anastomosis) between artery and vascular replacement. An „end to end“ anastomosis loaded by inner light increased constant systolic blood pressure is modeled in the thesis. The connection is modeled by different variants of the bonded contact and attachment of a surgical stitch. To solve the stress-strain state constitutive models were used in the finite element software package ANSYS 13.0. Material properties of arteries and vascular grafts were taken from measurements made at the Institute of solid mechanics, mechatronics and biomechanics.
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Stress-strain analysis of artery with atheroma
Maša, Marek ; Návrat, Tomáš (referee) ; Burša, Jiří (advisor)
The main goal of this diploma thesis was the stress-strain analysis of iliac artery with atheroma.This problem was solved using finite element method (FEM).For the calculation purposes three two-dimensional models were created. The geometry was gained from transversal sections through the iliac artery with ateroma. This geometry is educed from used literature review. The main calculation process was run by ANSYS 11.0 program system.
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Influence of mechanical properties of vascular grafts on their clinical applications
Chomič, Dimitrij ; Polzer, Stanislav (referee) ; Burša, Jiří (advisor)
The theme of my bachelor’s thesis is the vascular replacement. I write about the types of blood vessels, their anatomy, physiology, pathology and mechanical characteristics. My thesis contains a part about the types of vascular replacements, I define their mechanical characteristics and I describe how the vascular replacement used in medicine. I study the artificial vascular replacement preferentially. To illustrate the application of the moment theory of cylindrical shells (Course in PP II), I solve the extreme stresses in the connection of a replacement with a vessel having mutually different geometrical and material parameters. The artery and the replacement were under pressure of 16 kPa corresponding to the systolic blood pressure.
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CT angiography vs. ultrasound imaging of the bloodstream - efectivity, limitation and impact on patients' health.
ADAMEC, Jaroslav
The subject of the BA thesis is "CT angiography vs. ultrasound imaging of the bloodstream - efectivity, limitation and impact on patients' health". Examination of blood vessels by computed tomography - CT angiography, using modern equipment and technological development, takes over the diagnostics of vascular diseases from digital subtraction angiography primarily due to the speed of the examination and the lesser invasiveness with regard to the patient. The second method treated in this thesis is ultrasonography. Which of these imaging methods yields better diagnostic information on blood vessel pathologies? Which entails fewer risks to the patient and which is more limited? I have tried to find the answers to these questions in this BA thesis. In this thesis I set out to find which of the two imaging modalities is more suitable for examining vascular diseases. A further aim of the thesis is to introduce and compare various examination methods of computed tomography and ultrasonography. The hypothesis of the BA thesis states: "Ultrasonography is a more suitable method for the examination of the blood vessel tree - it is a method which provides good diagnostic information and at the same time entails a lower risk to the patient than does computed tomography". The introductory part of the thesis is devoted to the anatomy of the blood vessel tree. It describes main blood vessels, veins, their construction and branches. This part also introduces the technological equipment which is used for the examination of the blood vessel tree - computed tomography machine, ultrasonography machine - and their historical development. The basic physical principles of these devices, their methods of imaging and general methods of the examination of the blood vessel tree are also described in this chapter. In the case of computed tomography it is CT angiography, and in ultrasonography it is Doppler examination. The chapter also briefly deals with the advantages and disadvantages of these methods and with the contrast media which are applied in connection with the examination of the vascular system. I have studied all available specialized literature and web sites related to the subject for the purpose of writing this BA thesis. Data from the Institute of Health Information and Statistics were used for the analysis of the technological equipment. Data from the information network of the R+S Benešov a.s. hospital were used for the analysis of the number of blood vessel examinations carried out by ultrasonography and computed tomography. Examination methods of the vascular system performed by computed tomography and ultrasonography have been summarized in the result. Furthermore, both modalities are compared in this chapter with regard to their utilization rate, limitations and risks. The chapter also includes an analysis of the data on the computed tomography and ultrasonography technology in the Czech Republic and on the number of blood vessel examinations carried out by computed tomography and ultrasonography. In the chapter "Discussion" I present my own opinion on the given matter. It also includes a reflection on the issue of indicating examinations on computed tomography. In the conclusion of the thesis, examination methods of the vascular system by computed tomography and ultrasonography are assessed, and established findings on the studied matter are summed up. After studying all available specialized literature I have found that it is impossible to determine which of the two imaging methods is more suitable for the examination of the blood vessel tree because each of them has its specific advantages and disadvantages. The two modalities are thus not opposed to each other in the decision making which method should be indicated; on the contrary, the two methods should be used in close collaboration. The hypothesis of the thesis therefore has not been proved.
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Function of radiographer at embolization procedure
KŘÍŽOVÁ, Pavlína
As a radiographer can be regarded an educated health worker who is prepared to perform demanding work in medical branches. One of them is radiology and its important subspecialty, interventional radiology, where they perform a very responsible work. They communicate with patients, cooperate with medical personnel and operate a complex angiographic apparatus. Therefore it is essential for them to have finished a profes-sional training and to possess the required qualities. A person becomes a radiographer after they have completed a specialised educational programme, which can nowadays be studied at a college and it is completed by achieving a title Bc. (written before the na-me). During the studies they acquire proficiency and competence in the field of radiology which is needed for the experience in the interventional radiology working place. During both theoretical and practical education skills in the field of technical equipment (angiography equipment) and required IT technologies (HIS, PACS) are mastered, as well as the anatomic orientation in examinated area. They learn the latest procedure in the embolization techniques from the medical personnel, orientate themselves in the instrumentarium. Moreover, they are accustomed to the contrasting materials and their undesirable reactions to them. If needed, they are fully able to give the first aid.In addi-tion to that, a non-medical personell who participate in carrying out the embolizations should possess following qualities: communication skills - proficient cooperation with the medical personnel and the patients, empathy - patient awareness, ability to handle stressful situations. Working with an ill person demands a psochologically accurate individual approach and strict following of the medical ethic principles. Embolization is a way of occluding (closing) one or more blood vessels that are doing more harm than good. Various materials may be used, depending on whether vessel occlusion is to be temporary or permanent, or whether large or small vessels are being treated. The material is passed through a catheter with its tip lying in or near the vessel to be closed. This approach can be used to control or prevent abnormal bleeding as well as shut down the vessels that support a growing tumor. Therapeutic embolization may also serve to eliminate an arteriovenous malformation (AVM), an abnormal connection between an artery and a vein. The term "embolization" derives from embolus, which can be any object that circulates in the bloodstream until it lodges in a blood vesel - in this case, a synthetic material or medication specially designed to occlude the blood vessels.
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