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Contrast MRI perfusion imaging
Šejnoha, Radim ; Harabiš, Vratislav (referee) ; Krátká, Lucie (advisor)
This semestral thesis is focused on contrast MRI perfusion imaging using method of Dynamic Contrast-Enhanced MRI. It describes basic principles of nuclear magnetic resonance and puls sequences used in DCE MRI. The thesis contains a part dedicated to dynamic contrast imaging of phantom with experimental NMR device located at the Institut of Scientific Instruments of the ASCR in Brno. Results of measurements are analyzed based on models and reached perfusion parameters are discussed.
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Modelling of parametric arterial input function in perfusion imaging
Černý, Štěpán ; Jiřík, Radovan (referee) ; Kratochvíla, Jiří (advisor)
The task of this bachelor’s tesis is to study the subject in the area of perfusion imaging based on dynamic imaging with T1 contrast. Aims is primarily on the role of the arterial input function. Principles phenomenon of dynamic magnetic resonance measurements are discribed. The role of contrast media and their influence on the relaxation time T1 are described. It is also described problems perfusion analysis, measurement and mathematical modeling of arterial input function and perfusion acquisition parameters. In the experimental part, there is modeled several models of arterial input function and their evaluation. Further the creation program for the approximation real measurement of arterial input function created models and the integration of this program into a graphical interface created for work with models. Was also verified the functionality of the program and evaluate the success of approximations for individual models.
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Using multi-echo sequences in DSC-MRI
Černý, Štěpán ; Jiřík, Radovan (referee) ; Macíček, Ondřej (advisor)
The task of this thesis is to study the subject of perfusion analysis based on dynamic imaging with T2/T2* contrast. The focus was on the acquisition commonly used for DSC-MRI and especially in the acquisition pulse sequences that use images with different echo time, so called Multi-echo sequence. Principles of dynamic measurement by magnetic resonance imaging, the role of contrast agents and their influence on the relaxation times are described. It also describes the problems perfusion analysis, measurement and mathematical modeling parameters entering to the convolution dependency for getting perfusion parametersIn the experimental part is developed automatic algorithm to gain curves relaxation time T2 *. Next, the synthetic data are created and tested robustness estimate perfusion parameters against noise. In the next phase of work there are compared real scanned objects with using a conversion with T2 * and free of T2*. In the last phase of work is compared influence of length of used echo times on concentration curves and after perfusion analysis influence on resulting perfusion parameters.
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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.
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Model of dynamic contrast CT data for verification of registration algorithms
Kupková, Karolína ; Harabiš, Vratislav (referee) ; Walek, Petr (advisor)
This work is focused on the description of the dynamic contrast-enhanced CT examination and its contribution in the pneumooncology. It includes a program for creating a two-dimensional model of the scan from the thorax and for the perfuse examination simulation using the time-density curve. Real CT data are simulated more authentic using rigid geometric transformations and noise. The model will be used for the validation of registration algorithms that is used to suppress the spatial deformation generated by patient motions during the long time examination.
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MRI Acquisition of Image Sequences for Preclinical Perfusion Imaging
Krátká, Lucie ; Bartoš, Michal (referee) ; Jiřík, Radovan (advisor)
The task of this thesis is to study methods for the acquisition perfusní imaging based on dynamic MR imaging with T1 contrast. It describes methods of measurement of T1 relaxation time and the possibility of evaluating the results. It further describes the phantoms and their use. And it is here mentioned for the dynamic acquisition protocol perfusní imaging. There is also described in detail created a program for automatic control of the NMR system. In the experimental measurements are performed on static and dynamic phantom, are also evaluated perfusion parameters from the Flash sequence.
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MRI Acquisition and Preprocessing of Image Sequences for Clinical Perfusion Imaging
Krchňavý, Jan ; Bartoš, Michal (referee) ; Jiřík, Radovan (advisor)
This thesis describes the theory for static and dynamic magnetic-resonance imaging using contrast agents affecting T1 relaxation time. The available acquisition methods in the specified facility of Masaryk Oncological Institute in Brno are described. The sequences for subsequent experimental measurements are selected. The used phantoms are described. Acquisition protocol for measuring is described briefly and the evaluation method for the measured data is suggested. The best acquisition sequence and a method of measurements is chosen influenced by estimation of relaxation time T1, sensitivity and signal to noise ratio. Perfusion analysis is executed and perfusion parameters are calculated. The work was supported by the European Regional Development Fund and the State Budget of the Czech Republic (RECAMO, CZ.1.05/2.1.00/03.0101).
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Investigative algorithm of the gastrointestinal tract
BAUEROVÁ, Anna
Digestive diseases are increasing constantly due to the lifestyle of the people. For that reason number of the people with necessity to have some of the radiodiagnostic examinations of the digestive tract is increasing. The radiodiagnostics is one the fundamental pillars to discover not only cancers, but also other digestive diseases. Every part of the digestive tract has its specific and unique role and may be affected by a disease. A wide range of diseases may be very dangerous given the digestive function importance. So, it is necessary not to underestimate disease signs and to detect the disease at the earliest stages. The bachelor thesis Gastrointestinal tract examination algorithm resumes the methods necessary to early and proper diagnosis of the structural, functional and other diseases. The theoretic part of the bachelor thesis includes an overview of the radiodiagnostic methods used to examine particular parts of the gastrointestinal tract. The direction of the particular digestive tract part description is craniocaudal. Every digestive tract part contains examination progress description, patient preparation and a list of the most common indications. Additionally, the paper includes a chapter about the liver, bile ducts, pancreas and spleen. The bachelor thesis aims are to create algorithms to examine the gastrointestinal tract using radiodiagnostic examination methods along with information leaflets which may make a contribution to patients better knowledge before gastrointestinal tract examination. Quantitative data collection method is used in the practival part. The anonymous questioning method was used to get responded the research questions about the preliminary information of patients before the gastrointestinal tract examination and preference regarding the oral or written form of communication. The questionnare contains 13 closed questions regarding the patient information on the received examinations. The questionnares were answered by the patients receiving a gastrointestinal tract examination at the radiodiagnostic department of the Hospital of České Budějovice a. s. and at another anonymous hospital. In total 66 respondents got the questionnares of which 64 has been returned. Gathered data were evaluated, then sorted and processed into graphical output including descriptions. The results confirmed legitimacy of the initial research question and the fact that patients feel to be enough informed. Nevertheless, there is obvious the information should be continually improved in quality. The results indicate that patients like live interviewing with health care personnel as well as having the written information - leaflets, brochures. This finding also answered the second research question of the thesis. The bachelor thesis output presents a coherent review including the description of radiodiagnostic methods to examine gastrointestinal tract. The results are prepared for the real use in form of leaflets. This means fluoroscopy of pharynge, esophagus, stomach and duodenum, digestive tract, enteroclysis, CT enteroclysis, CT enterography, MRI enterography, irigography, defecography, virtual CT colonoscopy, ultrasonography, ERCP and PTC. The leaflets are aimed to prepare patient for various upcoming examinations completed with adequate psychosocial information. Also the information associated with pain or accompanying person, hospital stay, etc. were included. The leaflets are created to be easy to understand. The leaflets are to avoid specific technical terms as much as possible.
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Examination of the urogenital system Hospital Department of Radiology Jablonec nad Nisou p.o.
MENŠÍKOVÁ, Věra
The bachelor thesis named Examination of the urogenital system Radiodiagnostics Hospital Jablonec nad Nisou c. o. deals with methods of examination of the genitourinary system and creates a list and description of each method, using at these examinations. A radiology assistant is a non medical healthcare expert who uses their theoretical and practical knowledge gained during their university study in the fields of radiodiagnostics, radiotherapy and nuclear medicine. Radiology assistants are erroneously perceived both by other medical personnel and by lay public as technical workers. However, they are also medics who must be able to manipulate with highly sophisticated equipment but also provide medical care to the patients in full scale. As regards radiodiagnostics, the radiology assistants' task is to carry out the examination itself and obtain graphic documentation thereof. Radiology assistants ensure examination and handling of the equipment and they assist the doctor radiologist during more exacting intervention procedures. Radiology assistants' job is highly erudite and people working with ionising radiation must strictly abide by the laws and regulations stipulating strict rules and requirements which each radiology assistant must meet when they want to perform this activity. Radiology assistants' approach must help reduce the radiation burden of the population. It is logical, that the technological development goes hand in hand with higher examination yield and the ALARA principle is generally adhered to and applied in all examinations. If we strive to decrease the radiation dose, it is necessary to use an optimum amount of contrast agents. At the beginning of the thesis, there is a detailed description of urogenital system anatomy and physiology whose knowledge is a must when one wants to work in this field. Imaging methods described in the thesis range from the simplest ones to the most complex ones, both as regards the examination time and pursuant to specifications associated with individual examination types. The examination should be carried out from the least invasive examination procedures to the most complex ones. The methodics is based on gathering, study and subsequent analysis of the obtained data. Data from years 2009 2013 obtained at the radiodiagnostic ward of Nemocnice Jablonec nad Nisou p.o. hospital was gathered for this purpose. Investigations are divided into a number of men and women undergoing these tests. Investigative methods are compared, and evaluated that prevail, and from which they are abandoned prevail and which are being gradually abandoned. For the purpose of my thesi. The gathered data was processed into tables and synoptic graphs. Information from expert books, articles and verified Internet sources were used in the bachelor thesis. Results of my study confirmed the research question, the number of patients who undergo examinations of the urogenital system Radiodiagnostics Hospital Jablonec nad Nisou after rising. Preference tests are noninvasive and greater diagnostic yield. It is also found, however, that certain examination still have their place and are being replaced by another method. This example of hysterosalpingography. The aim of the thesis was to create an overview and description of individual radiodiagnostic methods in uropoetic system examinations and analysis of data from radio diagnostic department Hospital Jablonec nad Nisou regarding the examination of the urogenital system. The number of examinations in the radiodiagnostic ward is rising and the demands placed on a radiodiagnostic assistant are also continuously increasing from both physical and mental point of view. Radiology assistants are obliged to improve their knowledge and skills actively by means of training sessions and self study.
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