|
|
Image objects detection based on the feature points matching
Trávníček, Vojtěch ; Macíček, Ondřej (referee) ; Harabiš, Vratislav (advisor)
This paper is concerned in branch of computer vision. Methods for extracting feature points are presented as tools for image comparison and finding objects in images. Four methods are metioned which are compared with respect to their effectiveness and utilization. Algorythms SIFT and SURF are described as a state-of-the-arts. This paper also mentions methods for describing feature points and their comparison. Testing images are inserted as a tool for first testing of implemented algorythm. Finally, the implemented method SURF is described and tested with respect to several most relevant parameters.
|
|
|
Batch processing of perfusometric MRI data
Filipová, Petra ; Macíček, Ondřej (referee) ; Jiřík, Radovan (advisor)
This diploma thesis deals with the DCE – MRI method (Dynamic contrast enhanced magnetic resonance imaging). Basic principle of magnetic resonance and pulse sequence is described. The diploma thesis focuses on the DCE method, especially on the description of the processing procedure by this method. Description of selected pharmacokinetic models is the part of this diploma thesis as well. Furthermore, description and realization of batch processing by PerfLab system is presented. For verifying purposes of the batch processing functionality real data were measured using created acquisition protocol, which is also part of the diploma thesis.
|
|
|
Perfusion analysis using DSC-MRI method
Minsterová, Alžběta ; Jiřík, Radovan (referee) ; Macíček, Ondřej (advisor)
This bachelor thesis deals with the DSC (Dynamic Susceptibility Contrast) method, which is one of the magnetic resonance imaging methods using a contrast agent. It describes the principle of the magnetic resonance imaging, other methods of MRI using the contrast agent are mentioned. It further contains the DSC-MRI method, common used sequences and the description of a procedure of an imaging by this method. This thesis also focuses on the implementation of a graphical application in MATLAB, which copes with the perfusion analysis and the visualization of perfusion maps.
|
|
|
Contrast enhancement for tissue discrimination and contrast nanoparticle detection by MRI
Bačovský, Jaromír ; Macíček, Ondřej (referee) ; Starčuk, Zenon (advisor)
Magnetic resonance imaging is a routine and powerful diagnostic technique capable of providing detailed information about the structure and composition of the tissues. This diploma thesis is concerned with the mechanisms of contrast origin and contrast modifications by molecular and nanoparticle contrast agents. First sections of the thesis summarize basic knowledge about pulse sequences and it aims to provide an overview on MRI contrast agent with a special emphasis on paramagnetic gadolinium contrast agents and superparamagnetic nanoparticles. The main purpose of this study is to develop the software called MRICalc, which is able to optimize contrast in MRI images. Based on analysis of signal formula of typical pulse sequences, MRICalc is able to propose the parameters of the pulse sequence for compartment-specific enhancement of the contrast. User chooses from the list of the samples and after calculation he obtains the values of echo time, repetition time and flip angle, all of which simultaneously seem to create the appropriate setting to enhance the contrast. MRICalc also allows to plot contrast function with respect to the chosen parameter. Software, including its graphical user interface, is designed in Python. The sample consists from solution of CuSO4 and distilled water was designed to verify the correct function of MRICalc. Sulphate represents a contrast agent. Preclinical MR system Bruker BioSpec 94/30 USR located at Institute of Scientific Instruments of the ASCR, v.v.i was used to measure contrast curve of FLASH pulse sequence, which is a typical representative of gradient echo. Results of the measurement were compared to the theoretical model provided by MRICalc.
|
|
|
Development of parallel visualisation of subdermal regeneration by tomographic and hystological methods
Ruszová, Kristína ; Macíček, Ondřej (referee) ; Skopalík, Josef (advisor)
The aim of the thesis is to review suitable methods for quantifying the regeneration of subcutaneous layers and collagen structures in tissue defect, especially MRI methods and histological techniques. The theoretical chapters contains basic overview of skin anatomy and healing process, brief overview of histological methods and description of MRI as well. The practical part contains a description of data acquisition and optimization of methods for obtaining these MRI images with the best possible visualization of the condition of the skin layers. It also describes the designed software for comparing the acquired MRI images and the classical histological image from the tissue post-mortem. Finally, the evaluation of suitable modifications of gels and coatings that would affect the contrast characteristic of these planar medication layers is summarized.
|
|
|
Advanced Methods of Perfusion Analysis in MRI
Macíček, Ondřej ; Frollo, Ivan (referee) ; Mikl, Michal (referee) ; Jiřík, Radovan (advisor)
This dissertation deals with quantitative perfusion analysis of MRI contrast-enhanced image time sequences. It focuses on two so far separately used methods -- Dynamic contrast-enhanced MRI (DCE-MRI) and Dynamic susceptibility contrast MRI (DSC-MRI). The common problem of such perfusion analyses is the unreliability of perfusion parameters estimation. This penalizes usage of these unique techniques on a regular basis. The presented methods are intended to improve these drawbacks, especially the problems with quantification in DSC in case of contrast agent extravasation and instability of the deconvolution process in DCE using advanced pharmacokinetic models. There are a few approaches in literature combining DCE and DSC to estimate new parameters of the examined tissue, namely the relaxivity of the vascular and of the interstitial space. Originally, in this scheme, the 2CXM DCE model was used. Here various models for DCE analysis are tested keeping in mind the DCE-DSC combination. The ATH model was found to perform better in this setting compared to 2CXM. Finally, the ATH model was used in alternating DCE-DSC optimization algorithm and then in a truly fully simultaneous DCE-DSC. The processing was tested using simulated and in-vivo data. According to the results, the proposed simultaneous algorithm performs better in comparison with sequential DCE-DSC, unleashing full potential of perfusion analysis using MRI.
|
|
|
Data Transfer via Ethernet
Kutílek, Miloš ; Macíček, Ondřej (referee) ; Sekora, Jiří (advisor)
This thesis deals with the transmission of information over the Ethernet network. In this work a suitable microcontroller and a communication module were selected. The Module provides data transfer from Ethernet to SPI bus. Furthermore an optimal digital temperature sensor DS1820 was chosen. Theoretically it describes the model TCP / IP and the Ethernet type network . In this thesis a block circuit diagram is created, further an electrical wiring diagram and a printed circuit board were constructed. In the programming environment BascomAVR a program is compiled, which is used to transfer information from the microcontroller via Ethernet to a website.
|
|
|
Laboratory exercise for RTG imaging systems
Kuchař, Otakar ; Macíček, Ondřej (referee) ; Mézl, Martin (advisor)
The aim of this Bachelor thesis is to study the X-ray and computed tomography. The theoretical section explains the basic physical principles, elementary particle, atom and ionizing. The following parts of the thesis deal with topics from the origin and various types of X-ray, to interaction of X-ray with tissue and X-ray detection. For computed tomography the thesis also explains data collection, the reconstruction of image using simple back projection, filtered back projection and algebraic reconstruction. In the practical part are analysed several measurements which were taken in the X-ray chamber designed for educational purposes by Leybold. The topics solve the attenuation of X-rays depending on the type and thickness of the material and the spectrum of the X-ray radiation. In the field of computerized tomography solve tasks as the change of contrast, parameters of acquisition and methods for reconstruction. The work includes prepared sample solutions to a laboratory experiments.
|
|
| |
|
|
Perfusion analysis using DSC-MRI method
Minsterová, Alžběta ; Jiřík, Radovan (referee) ; Macíček, Ondřej (advisor)
This bachelor thesis deals with the DSC (Dynamic Susceptibility Contrast) method, which is one of the magnetic resonance imaging methods using a contrast agent. It describes the principle of the magnetic resonance imaging, other methods of MRI using the contrast agent are mentioned. It further contains the DSC-MRI method, common used sequences and the description of a procedure of an imaging by this method. This thesis also focuses on the implementation of a graphical application in MATLAB, which copes with the perfusion analysis and the visualization of perfusion maps.
|
guest ::
