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Image Registration - Application in ophthalmology and ultrasonography
Harabiš, Vratislav ; Matula,, Petr (referee) ; Zemčík, Pavel (referee) ; Kolář, Radim (advisor)
Image registration is widely used in clinical practice. However image registration and its~evaluation is still challenging especially with regards to new possibilities of various modalities. One of these areas is contrast-enhanced ultrasound imaging. The time-dependent image contrast, low signal-to-noise ratio and specific speckle pattern make preprocessing and image registration difficult. In this thesis a method for registration of images in ultrasound contrast-enhanced sequences is proposed. The method is based on automatic fragmentation into image subsequences in which the images with similar characteristics are registered. The new evaluation method based on comparison of perfusion model is proposed. Registration and evaluation method was tested on a flow phantom and real patient data and compared with a standard methods proposed i literature. The second part of this thesis contains examples of application of image registration in~ophthalmology and proposition for its improvement. In this area the image registration methods are widely used, especially landmark based image registration method. In this thesis methods for landmark detection and its correspondence estimation are proposed.
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Perfusion Modelling in Optical Coherence Tomography
Štohanzlová, Petra ; Penhaker,, Marek (referee) ; Kudrna,, Petr (referee) ; Kolář, Radim (advisor)
This thesis deals mainly with perfusion modeling in optical coherence tomography (OCT). The introductory part deals with basic theory of the OCT, including a description of its basic applications. Part of the work was the testing of selected contrasting materials suitable for the OCT and the design and implementation of phantoms, which were subsequently used in the main part of the thesis. In the practical part, attention is paid to the perfusion analysis in the OCT, first the application of the dilution theory in the OCT for flow estimation, then a study testing the basic theory of perfusion on OCT by means of tissue phantom. Another part of the thesis is devoted to the method of speckle variance analysis for flow visualization.
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Theranostic systems in sonography
Říkovská, Klára ; Pekař, Miloslav (referee) ; Mravec, Filip (advisor)
This work deals with preparation of microbubble suspension from a mixture of phospholipids, palmitic acid and polyethylene glycol. Properties of prepared systems were studied using bubble tensiometry and dynamic light scattering method and were compared with commercial contrast agent SonoVue®. Suspensions were prepared in various conditions including different atmosphere and increased temperature in some steps of preparation and different solution. Effect of polyethylene glycol addition on surface activity of the system was studied. Surface activity of phospholipids was insignificant. Surface tension decreased with increasing concentration and molecular weight of polyethylene glycol in the system. Effect of different atmosphere and increased temperature showed no substantial trend. It emerged that dynamic light scattering is not suitable for this type of samples because of high polydispersity and phase separation of the system.
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Thermal lens spectrometric detection of MRI contrast agents in the process of their photocatalytic degradation
Petruľák, Michal ; Řezáčová, Veronika (referee) ; Franko, Mladen (advisor)
Diplomová práce je zaměřena na studium degradace kontrastních látek pro magnetickou rezonanci. Tyto látky se dnes ve velké míře používají v oblastech s rozvinutým zdravotnictvím. Můžeme je najít v odtocích z čistíren odpadních vod, což svědčí o tom, že běžné stupně čištění odpadních vod nejsou dostatečně efektivní pro jejich odstranění. O degradaci kontrastních látek na bázi gadolinia je jen málo informací. Fotokatalytický rozklad za pomoci oxidu titaničitého a také ozonace vybrané kontrastní látky gadobutrolu, byl sledován pomocí měření celkového organického uhlíku, mikroskopie termálních čoček a spektrofotometrie.
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The impact of the COVID-19 pandemic on work in radiology departments in selected hospitals in the Czech Republic
DOBIÁŠOVÁ, Marcela
In March 2020, the first patients with the disease COVID-19 began to appear in the Czech Republic, therefore measures had to be taken to protect both hospital workers and patients. Hospitals also had to respond to this situation,as health care providers. With the increasing incidence of the epidemic, covid units were created in hospitals, often at the expense of regular beds, but sometimes even entire departments. These restrictions also affected work in the radiology departments, where there were restrictions on planned examinations. The aim of the thesis was to analyze the impact of the COVID-19 pandemic on work in radiology departments and at the same time to analyze and structure examinations in radiology departments in the period from March 2019 to February 2021 in selected hospitals. In the theoretical part of the thesis, terms from the radiology department are defined, especially examination methods, contrast agents are described and divided, as well as their side effects. The next part is devoted to the principles of radiation protection, its use in the healthcare sector, the protection of radiological workers during the COVID-19 pandemic, the last chapter of the theoretical part presents the findings so far about the causative agent of the disease COVID-19, as well as the use of protective equipment. The research part introduces the results of a questionnaire survey among 64 respondents, describes what measures the hospital took to protect staff during the COVID-19 pandemic. The provided data on the number and structure of examinations from individual hospitals was evaluated and analyzed. 86 % of respondents answered that the COVID-19 pandemic affected the number and structure of examinations.
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Specifics of the radiodiagnostic examinations in the Hospital of Pelhřimov, p.o.
CHADIMOVÁ, Tereza
Nowadays, sciascopy examinations are increasingly being replaced by other examination methods, which include especially CT examinations, and therefore their number is gradually decreasing. The first goal of the bachelor thesis entitled "Specifics of radio diagnostic examinations in Pelhřimov Hospital, allowance organization", is to describe the history of the radio diagnostic department in Pelhřimov Hospital, allowance organization. The second goal is to analyze trends in imaging methods with a focus on Pelhřimov Hospital, allowance organization, between the years 2009-2018. In the theoretical part I mentioned the history of the radio diagnostic department in Pelhřimov Hospital, allowance organization, and I described contrast agents, their use and distribution. The largest part was devoted to the description of radio diagnostic devices used in Pelhřimov Hospital, allowance organization. These include ultrasound, X-ray machine, computed tomography or skiascopic-skiagraphic wall. Another part of my bachelor thesis contains a description of examinations performed on CT apparatus and skiascopic-skiagraphic wall in Pelhřimov Hospital, allowance organization. For the processing of the practical part I used data obtained from Pelhřimov Hospital, allowance organization, in the form of printed operation logs, with which I created tables. I divided the tables according to the types of examinations and the individual years and compared whether the spectrum of the individual types of examinations on the CT apparatus and the skiascopic-sciagraphic wall have changed in the past ten years. The contribution of this bachelor thesis serves as a background material for the staff of the radio diagnostic department in Pelhřimov Hospital. Furthermore, it is intended to inform the public and other health facilities.
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Synthesis of chelators for use in diagnostic imaging
Kretschmer, Jan ; Polášek, Miloslav (advisor) ; Kubíček, Vojtěch (referee) ; Hrubý, Martin (referee)
Metals play a crucial role in medicine as a part of therapeutic or diagnostic preparations. However, in the majority of cases, their properties cannot be utilized entirely in free ionic form. Organic molecules capable of chelation are used to open the full potential of the metal. The molecules are called chelators and are the core theme of this thesis. The most important function of these molecules is the chelation and coordination of the metal, but chelators can provide other important functionalities. This work, therefore, focuses on the design, synthesis, and application of such polyfunctional chelators and is divided into two parts: DO3A-Hyp This part of the thesis deals with chelators that can be used as amino acids to incorporate lanthanides into peptides. The developed chelators provide a short and rigid connection of the metal to the peptide chain. Tripeptides containing two units of such chelators with a central amino acid bearing a CF3 group were synthesized to demonstrate the capability of DO3A-Hyp building blocks. Two paramagnetic metals were combined within this tripeptide, and it was shown that such a rigid and locked system could be used for combining their magnetic susceptibility tensors. These magnetic susceptibility tensors were used for manipulation of the 19 F NMR shift of the CF3...
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Regiospecific cyclam derivatives for radiomedical and MRI utilizations
Blahut, Jan ; Kotek, Jan (advisor) ; Drahoňovský, Dušan (referee)
Cyclam (1,4,8,11-tetraazacyclotetradecane) derivatives are widely used for various purposes. In a medicine they are applied as ligands for radiometals applied as diagnostic or therapeutic agents against tumours, hypoxic brain tissues etc. In this thesis a new method for asymmetric cyclam derivati- ves preparation was developed. New cyclam derivatives with trifluoroethyl groups were prepared too. Paramagnetic metal complexes with these fluori- nated ligands can be used as contrast agents for 19 F-MRI. Keywords: Cyclam; Non-symmetric protection; Contrast agents; Trifluoroethylamines; Paramagnetic relaxation; 19 F-MRI.
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