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Ultrasound Image Sequence Segmentation
Gallo, Vladimír ; Walek, Petr (referee) ; Mézl, Martin (advisor)
This paper presents basic principles of ultrasonography, review of different modes of medical ultrasound imaging, principle of contrast-enhanced ultrasonography and review of basic techniques of image segmentation. The individual methods based on edge detection and region growing were implemented in Matlab. The performance of algorithms were tested in each category using synthetic and phantom image data.
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Image segmentation of ultrasound images
Schwarzerová, Jana ; Odstrčilík, Jan (referee) ; Mézl, Martin (advisor)
This bachelor’s thesis deals with basic description of ultrasonography, principles of contrast-enhanced imaging and application of segmentation methods in ultrasound problematics. Some individual methods were implemented in Matlab, version R2015b. Algorithms were tested on synthetic images data, on ultrasound phantom images data and on real ultrasound images. Then the thesis was extended by ultrasound sequences segmentation.
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Hydrogel fantoms in ultrasonic diagnostic
Chovancová, Aneta ; Sovová, Šárka (referee) ; Hurčíková, Andrea (advisor)
This Bachelor thesis is interested in hydrogel phantoms made from gelatin, agar and agarosa. The effect of food foil on the essential properties of gel matrixes such as drying and moulding has been investigated. These properties were investigated visually and gravimetrically. The speed of prepared gel matrixes was measured using high resolution ultrasonic spectroscopy depending on concentration. In the work, I follow up on the already performed Bachelor thesis [1], where gel matrices were measured in the environment of air and water. My gel matrices are dispensed to the machine's cell in a liquid state. Depending on the material used and the method of use of the food foil, gel matrixes prepared for visual and gravimetric evaluation from agar with a concentration of 3 % and 5 % without foil and with foil on the bottom were found to have a longer shelf life than other samples with the same use of foil. Gel matrixes of all three substances and all concentrations covered with food foil are able to last up to 20 days without massive drying and mould formation. The result of measuring the relative ultrasonic velocity of the hydrogels produced was found to increase the rate of spread of ultrasound for all measured substances as the concentration increased.
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Solubilization in sonographic systems
Überall, Martin ; Klučáková, Martina (referee) ; Mravec, Filip (advisor)
The aim of this thesis was to determine the solubilizing capacity of microbubbles based on SonoVue®, and phospholipids SonoVue® is made of, by using the UV-VIS spectrophotometry. The concentrations of solubilized substances within these systems was further determined. In particular, the properties of natrium dipalmitoylphosphatidylglycerole and distearoyl¬phosphatidylcholine were investigated. The microbubbles were produced using these phospholipids with the addition of polyethyleneglycol and palmitic acid. The solubilizing capacity was determined using hydrophobic solutes Sudan Red G, Oil Red O, 4-Di-2-Asp and Nile Red in order to obtain a model system of solubilized drugs or other hydrophobic substances. The behavior of solutes in phospholipids and our prepared microbubbles were examined in a moderately polar medium – physiological saline solution (0.15 M NaCl). The vizualization of prepared microbubbles was performed using optical and fluorescence microscopy. 4-Di-2-Asp, as a fluorescence probe, was not suitable for microbubble vizualization. The size of microbubbles that were produced during the experiment was almost the same as the size of microbubbles of commercially made SonoVue®. The concentration of solubilized hydrophobic solutes inside the liposomes of phospholipids ranged from tens to hundreds of micromoles per liter. With increasing concentration of phospholipids the concentration of solubilized solutes also increased. The results of this experiment can be used for further research focused on the solubilization of drugs in microbubbles, and contrast agents which are used in ultrasonography.
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Modelling for ultrasound perfusion imaging
Jakubík, Juraj ; Jiřík, Radovan (referee) ; Mézl, Martin (advisor)
This master thesis deals with the contrast agents and their application in the ultrasound perfusion analysis. It is focused on Bolus & Burst method which, as a combination of two approaches that have been used so far, allows an absolute quantification of perfusion parameters in the region of interest. Contrast agent concentration time sequence is modeled as a convolution of the parametrically defined arterial input function and the tissue residual funkction. Thesis discusses different mathematical models of these functions as well as the methods of the parameters estimation. The methods functionality is validated on simulated and also preclinical data.
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Modelling for ultrasound perfusion imaging
Hracho, Michal ; Šikner, Tomáš (referee) ; Mézl, Martin (advisor)
This thesis deals with the possibilities of determining perfusion parameters of vascular system, using contrast-enhanced ultrasound imaging, which is non-invasive method. Properties of ultrasonography and use of contrast agents are briefly summarized. The methods selected for perfusions analysis were Bolus-tracking¬¬, Burst-replenishment and both of them combined – Bolus&Burst. Parametric models based on these methods were created for modelling an approximation of set perfusion parameters with the use of blind deconvolution.
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Breast cancer - women's awareness of secondary prevention options
Košáková, Dominika ; Černý, Andrej (advisor) ; Laštůvka, Zdeněk (referee)
The topic of this bachelor thesis is breast cancer, which is one of the most common cancers in women from the Czech Republic. This thesis includes theoretical and practical part. The theoretical part was focused on the description of the issues related to breast cancer. Initially, it guides the reader through the anatomy and development of the female breast. The following chapters then introduce the reader to the different types of breast disease, either benign or malignant. Risk factors, symptoms of the disease, and current methods of diagnosis and treatment of breast cancer are also described. The last chapter elaborates on primary, secondary and tertiary prevention of breast cancer. In the practical part, two main objectives have been set. The first was to find out what is the awareness of women about secondary prevention and the second was to find out whether women are actively involved in it. These two objectives were further explored through nine sub-objectives. The research investigation was carried out using an anonymous, quantitative questionnaire survey conducted at the Gynaecology and Obstetrics Clinic of the First Faculty of Medicine of the Charles University in Prague. Data collection at the clinic took place from 1 November 2022 to 31 March 2023 and was carried out using a...
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Diagnostic imaging of patients with polytrauma
FIŠER, Martin
The bachelor thesis deals with diagnostic imaging methods in polytraumatized patients. Diagnostic imaging methods play a big role in the examination of these patients, where the main goal is an early diagnosis, which should help, in severe cases, even save the patient's life. This thesis is divided into theoretical and practical part. The first half of the theoretical part explains the definition of polytrauma and the mechanisms of its formation. The most common causes of multiple injuries are described. The second half describes the imaging methods that are used in the examination of polytraumas. First, I explain the basic radiological procedures and their algorithm in polytrauma. Then the thesis focuses on the principles of computed tomography, ultrasonography, skiagraphy and magnetic resonance. Contrast agents that we use in the diagnosis of a polytraumatized patient are listed. In the practical part, using the obtained data from the Hospital České Budějovice a.s., it was statistically examined whether the number of patients has increased over the past five years or not. In addition, the gender and age distribution of patients with polytrauma were investigated. The statistical representation of the causes of injury is also examined. The practical part also deals with what examination is performed most often. All data are clearly processed into tables and graphs. This bachelor thesis can serve as an educational material for students of medical disciplines and radiological assistants.
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Image fusion within prostate biopsy
ŽŮČEK, David
This study deals with the use of image fusion within prostate biopsy, which is a method used for several decades, which serves to accurately capture pathological findings in the prostate, primarily prostate cancer. The combination of imaging modalities, which are magnetic resonance and intracavitary ultrasonography, is used to guide the biopsy. The aim of the study was to study the unusual situation where one and the same radiological team performs both procedures at the same time. Procedures from which the prostate biopsy methodology guided by image fusion is formed. Subsequently, we established a hypothesis that specific benefits can be found when the same doctor and radiology assistant perform both procedures. Procedures which consists of image fusion of magnetic resonance imaging and intracavitary ultrasonography, which guide the prostate biopsy of the same patient. The methodology of the theoretical part was the study of mostly foreign professional medical articles and literature and the subsequent use of the information to clarify the described method. In the practical part, the output data of physical examination of 59 patients were processed with the use of ROC analysis and then compared with two foreign studies to verify the established hypothesis. The data were provided by Mr. MUDr. Zdeněk Chudáček Ph.D. The results of the ROC analysis and its comparison with foreign studies confirmed the hypothesis, and therefore the presence of specific advantages of the studied unusual situation of performing a prostate biopsy in the way determined at the beginning of this study. The results of this study will be used in a broader journal publication, which aims to bring the issue of this study to the professional radiological public.
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Hydrogel fantoms in ultrasonic diagnostic
Chovancová, Aneta ; Sovová, Šárka (referee) ; Hurčíková, Andrea (advisor)
This Bachelor thesis is interested in hydrogel phantoms made from gelatin, agar and agarosa. The effect of food foil on the essential properties of gel matrixes such as drying and moulding has been investigated. These properties were investigated visually and gravimetrically. The speed of prepared gel matrixes was measured using high resolution ultrasonic spectroscopy depending on concentration. In the work, I follow up on the already performed Bachelor thesis [1], where gel matrices were measured in the environment of air and water. My gel matrices are dispensed to the machine's cell in a liquid state. Depending on the material used and the method of use of the food foil, gel matrixes prepared for visual and gravimetric evaluation from agar with a concentration of 3 % and 5 % without foil and with foil on the bottom were found to have a longer shelf life than other samples with the same use of foil. Gel matrixes of all three substances and all concentrations covered with food foil are able to last up to 20 days without massive drying and mould formation. The result of measuring the relative ultrasonic velocity of the hydrogels produced was found to increase the rate of spread of ultrasound for all measured substances as the concentration increased.
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