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Arteries and veins segmentation in retinal images
Šumberová, Dagmara ; Odstrčilík, Jan (referee) ; Kolář, Radim (advisor)
This thesis deals with the necessity of vascular segmentation in digital image analysis of the retina and thein subsequent classification.It briefly describes the segmentation of vessels using matched filtering. Next part of this thesis is focused on processing of the retinal images, their manual segmentation and subsequent testing to determine the best discriminating parameters for classification. Finally there is an evaluation of measured parameters and the propřed extension of this method.
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Blood vessel segmentation in fundus images using mathematical morphology
Stonawski, Stanislav ; Jan, Jiří (referee) ; Odstrčilík, Jan (advisor)
Segmentation of retinal blood vessel is an important step in the fundus image analysis. The resulting image can be used to diagnose ophthalmic or cardiovascular diseases. The aim of this thesis is to search for possibilities of high resolution eye fundus image processing while using mathematical morphology methods. This should lead to the creation of an algorithm capable of blood vessel segmentation. The thesis provides information on fundus camera, image, blood vessel properties and mathematical morphology filtering methods. The created algorithms and the proposed method based on them are presented, including their performance analysis based on the HRF database processing.
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Analysis of temporal retinal sequences
Nováková, Marie ; Odstrčilík, Jan (referee) ; Kolář, Radim (advisor)
This thesis deals with a method of the retinal image acquisition by fundus camera, their properties and evaluation of the retinal vessel diameter from acquired images. Several studies dealing with usage of retinal vessels diameters for hypertension, cardiovascular diseases, diabetes mellitus and glaucoma are described. The second part of this thesis is focused on the extraction of the retinal blood-vessels pulsation from retinal sequences and the basic processing of extracted pulsation signals. The proposed method is described in details and tested on one dataset.
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Implementation of Algorithm for Recognition of Eye Retina
Ondroušek, Jan ; Stružka, Jaroslav (referee) ; Hájek, Josef (advisor)
Vessel structure is a very important element in medical sience for diagnosis of eye and cardiovascular diseases. Therefore, its automatic segmentation is very important too. In introduction there is a short description of eye retina. After that, method of implementation is presented according to Ing. Jan Odstrčilík's thesis - Analyze of colour retinal images aimed to segmentation of vessel structures created under the auspices of Brno University of Technology - Faculty of Electrical Engineering and Communication, Department of Biomedical Engineering in 2008. This method is based on filtering input image with properly designed filtering masks, followed by thresholding with properly calculated value and finally cleaning result image from artefacts. Algorithm was written in C++ language. All important functions were implemented for purpose of given method with consideration on speed and accuray. Main sections of source code with description of user interface are introduced next in this thesis. At the end, the implementation was tested on real images from ÚBMI and DRIVE databases, results were recorded, expansions and adjustments possibilities of implementation were debated.
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CT angiography vs. ultrasound imaging of the bloodstream - efectivity, limitation and impact on patients' health.
ADAMEC, Jaroslav
The subject of the BA thesis is "CT angiography vs. ultrasound imaging of the bloodstream - efectivity, limitation and impact on patients' health". Examination of blood vessels by computed tomography - CT angiography, using modern equipment and technological development, takes over the diagnostics of vascular diseases from digital subtraction angiography primarily due to the speed of the examination and the lesser invasiveness with regard to the patient. The second method treated in this thesis is ultrasonography. Which of these imaging methods yields better diagnostic information on blood vessel pathologies? Which entails fewer risks to the patient and which is more limited? I have tried to find the answers to these questions in this BA thesis. In this thesis I set out to find which of the two imaging modalities is more suitable for examining vascular diseases. A further aim of the thesis is to introduce and compare various examination methods of computed tomography and ultrasonography. The hypothesis of the BA thesis states: "Ultrasonography is a more suitable method for the examination of the blood vessel tree - it is a method which provides good diagnostic information and at the same time entails a lower risk to the patient than does computed tomography". The introductory part of the thesis is devoted to the anatomy of the blood vessel tree. It describes main blood vessels, veins, their construction and branches. This part also introduces the technological equipment which is used for the examination of the blood vessel tree - computed tomography machine, ultrasonography machine - and their historical development. The basic physical principles of these devices, their methods of imaging and general methods of the examination of the blood vessel tree are also described in this chapter. In the case of computed tomography it is CT angiography, and in ultrasonography it is Doppler examination. The chapter also briefly deals with the advantages and disadvantages of these methods and with the contrast media which are applied in connection with the examination of the vascular system. I have studied all available specialized literature and web sites related to the subject for the purpose of writing this BA thesis. Data from the Institute of Health Information and Statistics were used for the analysis of the technological equipment. Data from the information network of the R+S Benešov a.s. hospital were used for the analysis of the number of blood vessel examinations carried out by ultrasonography and computed tomography. Examination methods of the vascular system performed by computed tomography and ultrasonography have been summarized in the result. Furthermore, both modalities are compared in this chapter with regard to their utilization rate, limitations and risks. The chapter also includes an analysis of the data on the computed tomography and ultrasonography technology in the Czech Republic and on the number of blood vessel examinations carried out by computed tomography and ultrasonography. In the chapter "Discussion" I present my own opinion on the given matter. It also includes a reflection on the issue of indicating examinations on computed tomography. In the conclusion of the thesis, examination methods of the vascular system by computed tomography and ultrasonography are assessed, and established findings on the studied matter are summed up. After studying all available specialized literature I have found that it is impossible to determine which of the two imaging methods is more suitable for the examination of the blood vessel tree because each of them has its specific advantages and disadvantages. The two modalities are thus not opposed to each other in the decision making which method should be indicated; on the contrary, the two methods should be used in close collaboration. The hypothesis of the thesis therefore has not been proved.
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