Diplomová práce se zabývá detektory rentgenového záření pro mikro-CT systémy. Teoretická část zahrnuje standartní typy rentgenových detektorů a požadavky na kvalitu obrazu pro výslednou 3D rekonstrukci. V závěru jsou popsány fyzikální parametry reálných detektorů a metody jejich měření a vyhodnocení.

Stroke is a serious brain injury, which causes sudden death or terminates in permanent neurological disability. Nowadays, tissue plasminogen activator (tPA) is used as the only effective treatment of stroke. One of the potential targets for novel therapy are T cells. Even though the explicit role of T cells in the pathogenesis of brain injury, amounts and timing of all T cell subtypes infiltrating into brain during the stroke still needs further investigation. The research in this field is complicated by the lack of efficient methods for in vivo cell tracking. Therefore the aim of this thesis was to develop a method of T cells labelling by MRI contrast agent in order to investigate T cells distribution in ischemic mice model using in vivo MR imaging. T cells were isolated from C57/BL6 mice in two step isolation protocol using gradient centrifugation and magnetic separation with the efficiency of 97 %. The isolated cells were labelled with 100 μg Fe/mL of Molday ION Rhodamine B contrast agent. The labelling efficiency after 17 hours of cells incubation was higher than 99 %. The labelled cells were cultured with CD3 and CD28 antibodies resulting into the 74 % viability of labelled T cells compared to 83 % viability of non labelled T cells. The labelled T cells were visualized by fluorescent...

The master's thesis consists of two parts. The first part contains the azimuth -- slowness analysis for period 3s<=T<=6s, which was conducted by the FK analysis for 10 stations of the WEBNET network. In the second part there is the surface wave group velocity measurement for every station pair of 10 WEBNET stations. The interstation group velocity was obtained by the cross--correlation of microseismic noise records. Local group velocities are connected with the instantaneous period data. The Love wave group velocities are visualised by the 2D tomography calculation. The thesis also contains the additional Love waves dispersion analysis for just one station pair. Powered by TCPDF (www.tcpdf.org)

Lanthanide(III) complexes of DOTA derivatives are utilized in the medical imaging techniques such as magnetic resonance imaging (MRI), magnetic resonance angiography (MRA), and magnetic resonance spectroscopy (MRS), nuclear imaging (PET and SPECT), or optical methods (luminescence). It has been shown that relaxometric parameters of the Gd(III) complexes of DOTA derivatives with a phosphinic acid pendant arm (Gd-DO3APR ) can reach optimal values (e.g. water residence time, τM, being close to ~10 ns). The relaxometric parameters can be further modified through the phosphorus substituents. It is also known that the complexes possess a high thermodynamic stability and they are kinetically inert. The main goal of this Thesis is an investigation of the effect of pendant amino group protonation in substituents bound to the phosphorus atom on properties of the complexes. Thus in this Thesis, DOTA derivatives with the phosphinic acid pendant arm with an amino group and their complexes were prepared and characterized. The complexes are intended as contrast agents for molecular imaging techniques (mainly for MRI and 31 P MRS). The first part of the Thesis introduces two new versatile "phospha-Mannich" protocols performed under mild conditions. Amino-H-phosphinic acids (AHPAs) were synthesized with excess of...

Synthesis of monosubstituted β-cyclodextrin derivatives for medicinal applications Abstract This thesis is focused on preparation of a set of β-cyclodextrin derivatives with potential use as scaffolds for a construction of novel MRI contrast agents. Firstly, the skeleton of native β-CD was selectively persubstituted at possitions 6 and equipped with azide functions. Per-6-azido-β-CD was then monosubstituted on secondary face of the macrocycle. (E)-cinnamylbromide and propargylbromide were chosen as suitable reagents. The monosubstitution reaction afforded two types of regioisomers, substituted at position 2I -O- or 3I -O-. These regioisomers were sucessfully separated via preparative column chromatography after peracetylation of all free hydroxyl groups. 2I -O-, 3I -O-formylmethyl- and 3I -O- karboxymethyl- analogues were prepared by oxidative transformation of cinnamyl group. Finally the usability of the formylmethyl- derivative for covalent binding with suitable substrate via reductive amination was confirmed. Keywords: cyclodextrins, monosubstitution, cinnamyl, propargyl, formylmethyl, carboxymethyl, reductive amination, MRI, contrast agents

ABSTRACT This work is focused on the synthesis of a family of new macrocyclic ligands with exchangeable protons on coordinating groups that could potentially serve (after complexation with suitable paramagnetic lanthanide(III) ions) as responsive contrast agents (CAs) for magnetic resonance imaging (MRI). It is expected that measurement of extracellular pH should bring information for tumorous disease diagnoses and/or for suggesting the most efficient treatment. Therefore, our attention was focused on pH-dependent CAs based on a PARAmagnetic Chemical Exchange Saturation Transfer (PARACEST) mechanism capable of reporting pH changes in tissue. The PARACEST-related properties of a series of Ln(III) complexes with the CEST effect caused by amino groups coordinated to the central Ln(III) metal ions were investigated. Such a kind of PARACEST CA is new and has had no precedent in the literature. It was shown that these Ln(III) complexes produce a pH-sensitive PARACEST effect in the pH region relevant for living systems. The study brings proof-of-principle for utilization of complexes with a linear diamine pendant arm, i.e. complexes with two exchanging proton pools, for ratiometric pH determination by MRI independently on the probe concentration. In addition, to ensure a higher kinetic inertness of the...

Development and evaluation of new cementless revision acetabular components for total hip arthroplasty / type TC / Objective: The aim of the clinical part of the study was to introduce a new revision oval cup type TC, and evaluate its reliability and utility in revision endoprosthesis. Due to the different structure of the implant, we aimed to objectively demonstrate the remodeling of bone tissue in its vicinity. In the experimental part of the work we verified the hypothesis that the use of locking screws has an effect on the bond strength of the implant with bone tissue, and therefore on the primary stability of the acetabular component. Method: We evaluated 31 patients that underwent revision hip surgery between 2004 and 2008. The mean follow-up was 7.1 years (range 5.3 to 9.3 years, minimum 5 years after surgery). Osteointegration of the implant and remodeling of bone tissue around the implant and its ribs were evaluated by digital radiography and computed tomography, and clinical results according to Harris. The experiment was based on the execution of pull-out tests after the implantation of TC cups in cadaveric bovine pelves. We evaluated the dependence of tensile forces in the axis of the implant on extraction of the metal cup from the bone bed. Four tests were conducted with the cup fixed...

Composition analysis of urinary calculi with dual-energy computed tomography Urolithiasis is among lifestyle diseases. Question the timely and accurate diagnosis is still current. Therapeutic approach in dealing with kidney stones depends on the particular chemical composition of urinary stone. Since the end of the 20th century as a new diagnostic option in the problems of urolithiasis exploring the possibility of using techniques of DECT, which now brings the possibility of the material characteristics of tissues in vivo. The aim of the present study was to assess the accuracy of chemical analysis stone disease DECT correlation of the results with laboratory chemical analysis of urolithiasis. The research sample of patients with urolithiasis became of the 70 individuals who underwent examination using DECT focusing on the chemical analysis of urinary calculi in vivo. Subsequently, analysis was made of laboratory extracted urolithiasis in all these patients. With regard to the distribution of urolithiasis into 4 main types according to the chemical composition of the stone was then assessed compliance DECT and laboratory methods. Consensus of both analytical methods were investigated on a small set of blind investigated calculi of known chemical composition ex vivo. The main outcome of this work is...

Introduction: Left-ventricular (LV) distension and consequent pulmonary congestion are complications frequently discussed in patients with severe LV dysfunction treated with veno- arterial extracorporeal membrane oxygenation (VA ECMO). The goal of this study was to describe the influence of high VA ECMO flows to LV distension, lung hemodynamics, and lung fluid accumulation. Methods of LV decompression were studied to prevent lung edema. Methods: In all experiments porcine models under general anesthesia were used. The effects of high extracorporeal blood flow (EBF) on LV heart work were assessed in a chronic heart failure model. The effects of LV afterload on lung fluid accumulation were evaluated by electrical impedance tomography (EIT) on acute heart failure models. Phase and frequency filtration and mathematical analysis were applied to the raw EIT data. Subsequently, mini- invasive techniques of LV decompression were evaluated for LV work. Results: The stepwise increases of VA ECMO flow improved both hemodynamic and oxygenation parameters. Nevertheless, it also caused distension and increased work of LV. The rise in EBF led to increased pulmonary capillary wedge pressure and lung fluid accumulation assessed by EIT in heart failure. The methods for LV decompression (Impella pump, atrial...

Tato disertační práce pojednává o optimalizaci algoritmů pro rekonstrukci obrazu neznámé měrné vodivosti z měřených dat pořízených elektrickou impedanční tomografií. Danou problematiku zde věcně vymezuje několik různých prvků, zejména pak stručný matematický popis dopředné a inverzní úlohy řešené různými přístupy, metodika měření a pořizování dat pro rekonstrukci a přehled dostupných numerických nástrojů. Uvedenou charakteristiku rozšiřuje rozbor optimalizací parametrů modelu ovlivňujících přesnost rekonstrukce, způsoby paralelního zpracování algoritmů a souhrn dostupných zařízení pro měření tomografických dat. Na základě získaných poznatků byla navržena optimalizace parametrů matematického modelu, která umožňuje jeho velmi přesný návrh dle měřených dat. V této souvislosti dochází ke snížení nejistoty rekonstrukce rozložení konduktivity. Pro zefektivnění procesu získávání dat bylo navrženo zařízení k automatizaci tomografie s důrazem na cenovou dostupnost a snížení nejistoty měření. V oblasti tvorby numerického modelu byly dále zkoumány možnosti užití otevřených a uzavřených domén pro různé metody regularizace a hrubost sítě, a to s ohledem na velikost chyby rekonstruované konduktivity a výpočetní náročnost. Součástí práce je také paralelizace subalgoritmů rekonstrukce s využitím vícejádrové grafické karty. Předložené výsledky mají přímý vliv na snížení nejistoty rekonstrukce (optimalizací počáteční hodnoty konduktivity, rozmístění elektrod a tvarové deformace domény, regularizačních metod a typu domén) a urychlení výpočtů paralelizací algoritmů, přičemž výzkum byl podpořen vlastním návrhem jednotky pro automatizaci tomografie.