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Metal Artifacts Reduction in Dental CT Scans
Vágner, Dominik ; Juránková, Markéta (referee) ; Španěl, Michal (advisor)
Artifacts caused by the presence of metals in computed tomography scans impact their readability and can cause problems when making decisions for medical professionals. In recent years, deep learning-based methods have seen considerable success in solving this problem, compared to older hand-crafted solutions. In this work, two supervised neural network models (Autoencoder, U-net) are implemented, along with a better way to solve the problem of creating a synthetic dataset, as otherwise in this case it is naturally impossible to obtain. The results in evaluation metrics (PSNR, SSIM) achieved are on par with those of state-of-the-art solutions while reducing the need for prerequisites that are complicated to prepare. This generalized solution enables a broader and easier application without needing a specific controlled environment.
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Diagnostic imaging of patients with polytrauma
FIŠER, Martin
The bachelor thesis deals with diagnostic imaging methods in polytraumatized patients. Diagnostic imaging methods play a big role in the examination of these patients, where the main goal is an early diagnosis, which should help, in severe cases, even save the patient's life. This thesis is divided into theoretical and practical part. The first half of the theoretical part explains the definition of polytrauma and the mechanisms of its formation. The most common causes of multiple injuries are described. The second half describes the imaging methods that are used in the examination of polytraumas. First, I explain the basic radiological procedures and their algorithm in polytrauma. Then the thesis focuses on the principles of computed tomography, ultrasonography, skiagraphy and magnetic resonance. Contrast agents that we use in the diagnosis of a polytraumatized patient are listed. In the practical part, using the obtained data from the Hospital České Budějovice a.s., it was statistically examined whether the number of patients has increased over the past five years or not. In addition, the gender and age distribution of patients with polytrauma were investigated. The statistical representation of the causes of injury is also examined. The practical part also deals with what examination is performed most often. All data are clearly processed into tables and graphs. This bachelor thesis can serve as an educational material for students of medical disciplines and radiological assistants.
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Pediatric radiology - specifics of selected radiological examinations
ZACHAROVÁ, Martina
This bachelor thesis deals with the specifics of the examination of pediatric patients in the radiology department. The theoretical part describes how different is the work with children, not only in terms of developmental differences (anatomical, physiological and psychological), but also the established procedures which, if applied correctly, should lead to a reduction in the resulting radiation dose to the paediatric patient or his/her companion. Furthermore, in individual chapters, it introduces the reader in more detail to the specifics of the examination of children in the radiology department, specifically on X-ray (scans), computed tomography and magnetic resonance imaging. Within my practical part, two objectives were set in total. The first aim was to determine whether the accompanying person was sufficiently informed about the examination process - its advantages and disadvantages. The second aim was to find out which examinations are most frequently performed by children under 6 years of age in the radiology department. The questionnaire survey and data analysis of the radiology department of the Hospital České Budějovice a.s. was used. It was found that the accompanying persons were sufficiently informed about the ongoing examination, but they did not always understand the information sufficiently. The data analysis revealed that children were most often examined by means of scanography, skiascopy and magnetic resonance imaging. Only a small fraction of children were diagnosed by computed tomography, mainly because of the high level of ionising radiation a child receives during this examination. The main result is that applying experts are very careful about pediatric radiation hygiene. Children are first examined using modalities that impose very little burden. This is also helped by the correct education of the accompanying person, whose presence can calm the child or, if necessary, can hold the child.
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Issues of lung CT screening for smokers
POKORNÁ, Miroslava
The communication deals with the evaluation of the benefits of the Pilot Programme "CT screening of smokers' lungs". The objectives and methodology include a theoretical study of the anatomy of the airways and the emerging issues of lung cancer, smoking dependence, low dose CT chest scanning techniques, National Radiological Standards and the issues of the target group of smokers and their involvement in investigation and treatment at specialist centres. The research was conducted through a questionnaire survey of 50 smokers (total 25 questions) and 41 physicians (total 18 questions). As a result, it was found that smokers' patients' awareness of the program is not sufficient, mainly due to their lack of interest in CT scanning and treatment options for the consequences of smoking and their unwillingness to actively cooperate with health professionals in their health care, including their refusal to give up the smoking habit. The outcome of the survey of physicians is good awareness and commitment to the implementation of the Pilot Programme, but they are limited in numbers and workload. The survey shows that the Pilot Programme is beneficial to the population. Therefore, it could prospectively be implemented by a larger number of health facilities in our country as part of a screening programme and thus contribute to improving the health status of the population. It was also found that the Hospital Jindřichův Hradec a.s. meets the requirements and could be included in the Pilot Programme.
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The role of the radiographer in stomatology
STEINEROVÁ, Karolína
This bachelor's thesis focuses on radiological imaging methods and their use in dentistry. Radiological devices have been developing rapidly recently and have become a common part of dental outmous clinics. They are used not only in the field of dental and surgical dentistry, but also in aesthetic dental treatments. The thesis is divided into theoretical and practical parts. The aim is to map the advantages and disadvantages of each type of device and theri suitability of their use in dentistry. The theoretical part deals with basic anatomical concepts of the orofacial field, an overview of radiological diagnostic devices, their use in the field of dentistry and specially aesthetic dentistry, and the associated radiation protection of workers and patients. Furthermore, it focuses on the basic aesthetic anomalies of the teeth and their treatment, which usually precedes the imaging of the target area. The second part of the thesis was compiled on the basis of a questionnaire survey conducted. Two questionnaires were created concerning the use of imaging methods in the aesthetic repair of teeth, the equipment of dental workplaces and access to patients from the point of view of imaging and radiation protection from the point of view of patients and dentists. The aim was to answer research questions about the use of radiology in aesthetic dentistry and the level of information patients receive about their radiological examinations. According to research, the largest representation is the intraoral type of imaging, namely bitewing image, which is suitable for basic diagnosis of dental anomalies as well as changes in the structure of the tooth. This method is easy, fast and practically without any extra burden put on the patient. The most commonly performed aesthetic procedure turned out to be treatment with orthodontic apparatus, in which imaging of the original position of the teeth is necessary. The least used method in the field of dentistry is magnetic resonance imaging, due to the availability and creation of artifacts in images from dental metal fillings. Research shows that patients are not properly informed about the course, necessity or consequences of radiological examination. Although the dose of ionizing radiation is negligible in dental imaging examinations, the doctor should prevent and inform the patient of the patient's concerns. More than half of respondents consider X-rays to be health-burdensome.
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Usage of MR screening sequences in stroke diagnosis
PAVLIŠTÍK, Daniel
The bachelor's thesis on the topic of the use of MR examination sequences in the diagnosis of acute strokes is divided into a theoretical part and a practical part. The theoretical part generally describes the anatomy and pathological processes of the vascular supply to the brain. Stroke is undoubtedly one of the most common diseases, leading to death or serious damage. The incidence in the population has been increasing in recent years, not only in patients over 65 years of age, but also in people of working age. Furthermore, in the theoretical part we deal with the categorization of strokes and their clinical picture. The next chapter briefly describes the individual examination procedures for stroke with a more detailed description of imaging methods, especially computed tomography, CT angiography and CT perfusion. The next part of this thesis deals with magnetic resonance, which is another method used in the diagnosis of CMP, which is not used as often as CT. The advantage of this method is the sensitivity in the imaging of brain tissue and that this method doesn't use ionizing radiation. The disadvantages are the examination time, longer than with CT, and noise. The contraindication is mainly the presence of ferromagnetic material in the patient's body, pacemaker, cochlear implant. At the end of the theoretical part, we deal with the intervention of mechanical removal of thrombotic material, which is the cause of ischemia of brain tissue, prognosis and prevention of strokes. The research part processes data acquired from respondents who filled out a special questionnaire. The results of this work are summarized in the discussion and conclusion.
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Segmentation of cerebral vessels in volumetric data
Sucháček, Jan ; Harabiš, Vratislav (referee) ; Jakubíček, Roman (advisor)
This thesis deals with the design, implementation and testing of an algorithm for segmentation of cerebral vessels in 3D CT image data with a focus on stroke. First, a 3D binary mask of the brain was created and then used to extract brain tissue from the original volumetric CT images. In the extracted brain tissue, cerebral vessels were enhanced using three advanced filters based on Hessian matrix calculation and eigenvalue analysis of the Hessian matrix. The resulting parametric images of the enhanced cerebral vessels were input to six segmentation methods that were implemented and compared in this work. The program solution of this work was implemented in Matlab R2021b. The proposed algorithm was tested on real patient data. In one of the patient CT scans, cerebral vessels were labeled as part of this thesis and this resulting volume of manually segmented cerebral vessels was used to objectively evaluate the segmentation results obtained. In the theoretical part, the anatomy, physiology and pathology of the cerebral vascular supply were studied and described. Furthermore, the imaging methods used for imaging the cerebral vascular supply were described. A review of available segmentation techniques and specific approaches already published for segmentation of the cerebral vascular supply was performed. The methods used in this thesis were also theoretically described.
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Options computed tomography with high resolution in the diagnosis pulmonary complications in haematological malignancies
Mírka, Hynek ; Kreuzberg, Boris (advisor) ; Neuwirth, Jiří (referee) ; Heřman, Miroslav (referee)
Value of HRCT in the diagnostics of pulmonary complications of malignant haematologic diseases. Early diagnosis is one of the essential conditions for successful therapy of heamatologic malignancies and their complications. Imaging methods play an important role in their detection and patient's management. HRCT is the most contributing method in the diagnostics of pulmonary involvement, which is very common in this group of patients. The aim of this thesis was to find out the potential of this method in the diagnostics of pulmonary complications in patients with haematologic malignancy. For this purpose were assessed 4 objectives: 1) comparison between HRCT and chest X-ray; 2) determination of capability of HRCT to make a specific diagnose; 3) definition of indication criteria for HRCT and 4) assignment of the suitable examination technique. In the time period from January 2000 until December 2005 were performed 214 HRCT examinations of the lungs in the group of 162 patients with haematological malignancy and pulmonary symptomatology. 176 examinations were compared with chest X-ray, which was performed 48 hours or less before HRCT. Pulmonary lesion was discovered in 180 cases (84,1%). 123 findings were confirmed by another method (response to a specific therapy, cultivation, serology, BAL or...
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Monitoring of the relationship between the asymmetry of facial skeleton and the soft tissues based on computed tomography
Skryjová, Zuzana ; Velemínská, Jana (advisor) ; Bigoni, Lucie (referee)
The human face is not perfectly symmetrical, slight asymmetries commonly occur in every individual across all populations. The aim of the work was to monitor the asymmetry on the entire surface of the soft and hard tissues of the heads of individuals with respect to age and sexual dimorphism. The follow-up goal was then to evaluate the difference in asymmetry between the tissues. The material for the work was a transverse set of CT images of the adult Czech population in the age range of 21-84 years. Individuals were divided according to gender into 50 men and 48 women and according to age into groups up to 39 years, 40-59 years and over 60 years. Geometric morphometry methods (CPD - DCA, asymmetry analysis, per vertex T-test, superprojection methods) were used for data analysis. The results were visualized using color maps and significance maps that show asymmetry and statistical significance. The variability of the file was analyzed by principal component analysis. The results of the evaluation of hard tissues showed a right protrusion on the anterior and lateral surfaces of the skull, in both men and women at all age intervals. This asymmetry was statistically very significant, in contrast to the posterior region, which was evaluated protrusion on the left side and had lower p-value. On the soft...
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Image segmentation of spinal disc in medical imaging
Meloun, Jan ; Nemček, Jakub (referee) ; Mézl, Martin (advisor)
This thesis is focused on segmentation of intervertebral discs in images from two medical imaging modalities - computed tomography (CT) and magnetic resonance imaging (MRI). Theoretical introduction of the thesis describes intervertebral disc herniation and relevant imaging modalities. It also includes description of basic and advanced segmentation methods. For practical part of the thesis, three different segmentation teqniques (one for CT data and two for MRI images) have been chosen, implemented and applied on images acquired at Radiodiagnostic department of Havlíčkův Brod hospital. The segmentation quality has been assessed quantitatively for individual methods by comparing the segmentation results to manually created reference segmentation of intervertebral discs.
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