Unicuspid aortic valve (UAV), which is a rare congenital anomaly, usually presents as aortic stenosis and/or aortic regurgitation. Here we present a case of UAV co-existent with an ascending aortic aneurysm. A 26-year-old male with no significant past medical history presented to the hospital after two episodes of syncope. Transthoracic echocardiogram showed an ejection fraction of 62%, severely stenotic aortic valve, and moderate aortic regurgitation. Computed tomography revealed calcification of the aortic valve, compatible with aortic stenosis and aneurysm of the ascending aorta measuring 4.3 cm in diameter. He underwent successful aortic valve replacement and repair of ascending aortic aneurysm. He recovered well without any complications. This case suggests that any young patient who presents with syncope, aortic stenosis would be a differential and further workup by any available non-invasive modality needs to be performed.

Submitted in fulfilment of the requirements of the Master's Degree in Technology: Radiography, Durban University of Technology, 2013. / ABSTRACT Escalating current healthcare needs coupled with the dire shortage of radiologists created a climate in countries abroad to extend the role of the radiographer (Williams 2006). The South African radiography profession demonstrates similar if not worse challenges within the radiology services (Gqweta 2012). The human resource needs in the healthcare sector creates a gap in the provision of radiology services (Brandt et al 2007). Often under these circumstances radiographers are asked by emergency department's personnel to comment on radiographic appearances (Hardy and Snaith 2007). Radiographers do provide opinions in order to facilitate patient management (Gqweta 2012). Since the chest x-ray is the most commonly performed x-ray examination in x-ray departments (Manning, Leach and Bunting, 2000), it is assumed that most requests for an opinion may be directed for the clarification of this x-ray examination. Therefore radiographers need to have an in-depth understanding of the knowledge and skills related to the identification of patterns on chest images. The aim of the study was to establish and describe the current chest image interpretation skills, knowledge and perceptions of diagnostic radiographers in eThekwini Health District of KwaZulu-Natal (KZN) with regard to image interpretation. METHOD: A quantitative study using a descriptive design with a qualitative aspect using an interpretive design was employed. A simple random sample of hospitals within the eThekwini health district that have x-ray departments was drawn. All diagnostic radiographers that met the inclusion criteria from within these hospitals were invited to partake in the study and all were registered with the Health Profession Council of South Africa (HPCSA). A questionnaire was utilised to collect data on the perceptions and knowledge of diagnostic radiographers on radiographic appearances. A reporting template was provided for the respondents to report on ten (10) chest images and to standardise responses . Accuracy , specificity and sensitivity measurements were utilised to determine the image interpretation knowledge and skills of radiographers without formal training on image interpretation. The SPSS (Statistical Package for the Social Sciences) version 21 was utilised for the raw data capture and analysis. RESULTS Forty two (42) radiographers participated in the study. Almost half (46%) of the respondents were chief radiographers and twenty four point four percent (24.4%) of the respondents were senior radiographers . X-ray department managers and community service radiographers each had twelve (12%) percent representation. The majority of the respondents frequently performed chest x-rays. Furthermore they regularly observe Pulmonary Tuberculosis (PTB) abnormal patterns more than those of pneumonia and lung cancer on chest radiographs. The respondents indicated that there is a need for them to extend their roles to include image interpretation. This will ensure that radiographers are responsive to current health care needs perpetuated by the absence of radiologists and the ever rapidly increasing population. The majority of the respondents were able to identify abnormal appearances on the radiographs (high sensitivity). However there was a proportional decrease on the identification and recognition of the normal appearances (specificity). There was no respondent that obtained a mark of eighty (80%) on the image interpretation knowledge assessment section. CONCLUSION Radiographers are able to identify abnormal patterns on chest images. However they are unable to adequately exclude an abnormality (low specificity). Furthermore they lack the ability to adequately describe abnormal radiographic/radio logical appearances. The image interpretation knowledge base of radiographers is limited and specific. Therefore there is a need for an intensive education and training for prospective reporting radiographers.

published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy

published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy

Thermography is a useful tool for analyzing spinal nerve root irritation, but interpretation of digital infrared images is often qualitative and subjective. A new quantitative, computer-aided method for analyzing thermograms, utilizing the human dermatome map, is presented. Image processing and pattern recognition principles needed to accomplish this goal are discussed. Algorithms for segmentation, boundary detection and interpretation of thermograms are presented. An interactive, user-friendly program to perform this analysis has been developed. Due to the relatively large number of images in an exam, speed and simplicity were emphasized in algorithm development. The results obtained correlate well with clinical data and show promise for aiding the diagnosis of spinal nerve root irritation.

The high prevalence of back and neck pain results in enormous social, psychological, and economic burden. Most seeking help for back or neck pain consult general practitioners or chiropractors. Chiropractic is a regulated health profession (serving approximately 10 – 15% of the population) that has contributed to the health and well-being of North Americans for over a century. Despite available evidence for optimal management of back and neck pain, poor adherences to guidelines and wide variations in services have been noted. For instance, overuse and misuse of imaging services have been reported in the chiropractic literature. Inappropriate use of spine imaging has a number of potential adverse outcomes, including inefficient and potentially inappropriate invasive diagnosis and subsequent treatment, and unnecessary patient exposure to ionizing radiation. Although evidence-based diagnostic imaging guidelines for spinal disorders are available, chiropractors are divided on whether these guidelines apply to them. While guidelines can encourage practitioners to conform to best practices and lead to improvements in care, reviews have demonstrated that dissemination of guidelines alone is rarely sufficient to optimise care. Evidence regarding effective methods to promote the uptake of guidelines is still lacking. There is growing acceptance that problem analysis and development of interventions to change practice should be guided by relevant theories and tailored to the target audience. To date, very little knowledge translation research has addressed research-practice gaps in chiropractic. This thesis reports rigorous methods to: (1) assess practice and providers’ characteristics, (2) determine baseline rates and variations in spine x-ray ordering, (3) evaluate the impact of disseminating guidelines to optimise spine x-ray ordering, and (4) assess determinants of spine x-ray ordering and potential targets for change prior to the design of a tailored intervention. A mixed method using two disciplinary perspectives (epidemiology and psychology) was undertaken. A cross-sectional analysis of administrative claims data was carried out on a sample of chiropractors enlisted in a large American provider network. Despite available clinical practice guidelines, wide geographical variations in x-ray use persist. Higher x-ray ordering rates were associated with practice location (Midwest and South US census regions), setting (urban, suburban), chiropractic school attended, male provider, employment, and years in practice. The impact of web-based guideline dissemination was evaluated over a five year period using interrupted time series and demonstrated a stepwise relative reduction of 5.3% in the use of x-rays. Passive guidelines dissemination appeared to be a simple, cost effective strategy in this setting to improve but not optimise x-ray ordering rates. Focus groups using the theoretical domains framework were conducted among Canadian and US chiropractors to explore their beliefs about managing back pain without x-rays. Findings were used to develop a theory-based survey to identify theoretical constructs predicting spine x-ray ordering practice. Psychological theories and theoretical constructs explained a significant portion of the variance in both behavioural simulation and intention. Results from this thesis provide an empirically-supported, theoretical basis to design quality improvement strategies to increase guidelines adherence and promote behaviour change in chiropractic. Other researchers interested in improving uptake of evidenced-based information could use this method in their own setting to investigate determinants of behaviour among other professional groups. Future research may use knowledge gained to inform the development and evaluation of a theory-based tailored intervention to improve guideline adherence and reduce the use of spine x-rays among targeted providers.

O círculo arterial do cérebro (CAC) é objeto de estudo desde os princípios da anatomia moderna e ao longo dos séculos documentado e classificado de várias maneiras. Recentemente o desenvolvimento dos métodos diagnósticos por imagem e de ultraestrutura abriram um novo leque nas possibilidades de investigação. Neste trabalho o CAC foi avaliado por meio de exames por angiotomografia computadorizada, por angiorressonância magnética, fotografias de peças anatômicas, histologia, microscopia eletrônica por varredura e por transmissão. Verificou-se na amostra que o CAC possui tendência a simetria. Os achados foram similares na comparação entre os métodos de diagnóstico por imagem, porém não demonstraram todos os achados dos espécimes anatômicos. A metodologia utilizada permitiu verificar que as camadas das paredes das diferentes artérias podem explicar parcialmente as diferenças nos achados entre os métodos de imagem e as peças anatômicas. Os dados aqui apresentados revestem-se de grande importância clínica e cirúrgica uma vez que o CAC é um elemento chave na circulação cerebral. / The Willis Polygon (WP) has been studied since the beginning of modern anatomy and documented and classified over the centuries in various ways. Recently the development of diagnostic imaging methods and ultra structure opened a new range of possibilities in the investigation. In this work the WP was assessed by computer tomography angiography examinations by magnetic resonance angiography, photographs of anatomical specimens, histology, scanning and transmission electron microscopy. It was found that the sample has a tendency to the WP symmetry. The findings were similar when comparing the methods of diagnostic imaging, but did not show all findings of anatomical specimens. The methodology has shown that the different layers of the walls of arteries may partly explain the differences in findings between imaging and anatomical parts. The data presented here are of great clinical and surgical importance, once the WP is a key element in the cerebral circulation.

O uso crescente da Tomografia Computadorizada de Feixe Cônico (TCFC) na área odontológica tem permitido o aumento dos achados incidentais em exames que são realizados por outros fins. Dentre essas uma, das mais comuns e com impacto na vida dos pacientes é o ateroma calcificado das artérias carótidas (ACAC), e no seu diagnóstico diferencial existem as ossificações das cartilagens da laringe. Para correta identificação dessas calcificações são necessários conhecimentos acerca da localização anatômica, distribuição e sua morfologia, sendo que a TCFC fornece uma localização tridimensional (3D) acurada. Entretanto existem diferentes softwares de pós-processamento de imagens disponíveis no mercado, e não há na literatura estudos sobre a capacidade desses softwares para a visualização dessas estruturas. Esse estudo tem o objetivo de identificar essas calcificações supracitadas, nos softwares de visualização de TCFC, i-Cat Vision® e Invivo5®, nas reconstruções multiplanares e 3D em dois grupos diferentes, sendo um grupo de exames de indivíduos com fissuras labiopalatinas (HRAC) (50 exames de TCFC) e outro sem fissuras labiopalatinas (FOB) (100 exames de TCFC). Foram avaliados 150 exames (112 do gênero feminino e 38 do gênero masculino) de TCFC por dois observadores devidamente treinados e calibrados. Para o grupo sem fissuras labiopalatinas foi encontrada diferença estatística significante entre a idade e a quantidade de calcificações encontradas. Considerando todas as calcificações, foram encontrados 104 indivíduos com alguma calcificação, representando 69,33% da amostra, sendo que o grupo HRAC apresentou 88% e o grupo FOB 59%. Foi possível demonstrar diferença estatística significante ao se comparar a quantidade de calcificações entre os grupos avaliados. Foi assumido nesse trabalho que as reconstruções separadamente do programa Invivo5® seria a padrão- ouro, nesse momento o programa i-Cat Vision® foi considerado mais específico do que sensível. Foram identificados muito falsos positivos no programa i-Cat Vision® e menores resultados para falso-negativos. Esse trabalho não tem o propósito de identificar os ACAC nos exames de TCFC, mas incentivar e demonstrar que é possível visualizar tais calcificações e diferenciá-las umas das outra, lembrando-se da responsabilidade do dentista em prevenir um problema futuro ao paciente que pode levar a quadros de morbidade e mortalidade. / The widespread use of CBCT in Dentistry leads to an increasing of incidental findings regarding exams for different purposes. The most common incidental finding that impacts the patients quality of life is the carotid artery calcifications as well as the ossification of laryngeal cartilage which is the most common differential diagnosis for aterosclerosis. To identify this calcifications/ossification correctly it is necessary to know about its anatomic localization, distribution and morphology once that CBCT images may evidence an accurate 3D location. Therefore many different manipulations imaging software for CBCT technology is available and there is no research in the literature about the capacity of this software to visualize these calcification/ossification structures. This study aimed to identify these calcifications/ossification, in two different visualization softwares: i-Cat Vision® and Invivo5®, both in Multiplanar Reconstruction (MPR) and 3D reconstruction, in two different groups, where one was constituted of cleft lip and palate (50 CBCT exams) patients and the other by patients without cleft lip and palate (100 CBCT exams). Two calibrated and trained observers evaluated 150 CBCT exams (112 were female and 38 male). There was significantly statistical difference when comparing age and calcifications quantity for no cleft lip and palate group. When considering all calcifications in both groups, 104 patients in 150 (total number) showed some calcification/ossification, representing 69,33%. The percentage of calcification/ossification in the cleft lip and palate group were 88% whereas the other one evidenced 59%. And due to this difference, there was significantly statistical difference between these groups. Besides, the Invivo5® software was considered the gold-standard (multiplanar reconstruction and 3D reconstruction) to identify the structures previously mentioned; then i-Cat Vision® software showed more specificity than sensitivity comparing the results with the Invivo5®. Many false positives were identified in i-Cat Vision® and only some false negatives, showing again the characteristics of these softwares. This work was not intended to identify carotid artery calcifications in CBCT exams, but in fact the real purpose was to demonstrate that it is possible to identify calcifications/ossifications and differentiate one of another. It is always important to remember about the dentistry knowledge and responsibility to prevent patient coming disease that may lead to morbidity and mortality situations.

A ultra-sonografia foi o primeiro meio diagnóstico por imagem utilizado na investigação do encéfalo, mas foi substituído pela tomografia computadorizada na década de 70 e atualmente por outros métodos como a ressonância magnética. O exame ultra-sonográfico continua sendo empregado em pacientes pediátricos e em animais jovens, cujas fontanelas permanecem abertas, servindo como janela acústica. Contudo, sua utilização em animais adultos fica restrita, em parte pela barreira proporcionada pelos ossos do crânio. Este trabalho objetivou: avaliar a possibilidade da utilização da ultra-sonografia transcraniana em cães adultos; estabelecer um paralelo com as imagens tomográficas; correlacionar as imagens sonográficas e tomográficas com a anatomia e comparar as imagens ultrasonográficas do encéfalo obtidas com e sem a interposição dos ossos do crânio. Foram utilizados dez cadáveres de cães adultos. As imagens tomográficas foram adquiridas em cortes transversais e dorsais com espessura de 5 mm e igual incremento. As imagens ultra-sonográficas foram obtidas através dos ossos temporal e porção lateral do parietal, da região frontoparietal dorsal íntegra e após craniotomia e do forame magno, em cortes transversais, dorsais e sagitais. Nesse estudo foi possível obter imagens do encéfalo dos dez cães através dos ossos temporal e parietal, evidenciando-se o tecido cerebral, os ventrículos laterais, a fissura longitudinal, alguns sulcos cerebrais, o cerebelo, o tentório do cerebelo, a região do diencéfalo e do hipocampo. A ultra-sonografia realizada através da craniotomia mostrou um bom detalhamento das estruturas anatômicas, superior ao obtido com a interposição óssea e nas imagens tomográficas. Não houve formação de imagem pelo osso frontal íntegro. Foi possível a visibilização apenas do cerebelo pela janela proporcionada pelo forame magno. As imagens tomográficas permitiram a visibilização direta do tecido cerebral, dos ventrículos laterais, do tentório ósseo do cerebelo. Muitas outras estruturas foram identificadas a partir da topografia e da sua relação com estruturas adjacentes. Concluiu-se que é possível avaliar o encéfalo de animais adultos através da ultra-sonografia utilizando como janela acústica os ossos temporal e a porção lateral do parietal. Contudo, a resolução das imagens é inferior quando comparadas àquelas realizadas com a fontanela aberta ou em craniotomias. Embora a tomografia computadorizada seja um excelente método para obter imagens seccionais, sem sobreposição de estruturas e uma maior diferenciação entre os tecidos moles, várias estruturas não são visibilizadas diretamente. Conhecer previamente a anatomia da região estudada é um pré-requisito importante para a adequada interpretação dessas imagens. / Ultrasound was the first medical technology performed for diagnostic imaging of the brain, but in the 70\'s the computed tomography became accessible, and recently, magnetic resonance imaging. Ultrasound imaging of the brain can be performed through the fontanelles in young animals. However, its using in mature dogs is restrict by the barrier presented by the bones of the skull. The purposes of this study were: evaluate of using ultrasound imaging of the brain in mature dogs; compare ultrasound with computed tomography imaging; correlate ultrasound and computed tomography features with the anatomy; compare the brain ultrasound images performed through a transosseous window with ultrasound images performed through craniotomy. Ten postmortem mature dogs were examined. Computed tomography scaning was obtained in transversal and dorsal planes, section thickness of 5mm and 5 mm intervals. Ultrasound imaging was performed through the temporal and parietal bones, dorsal frontoparietal before and after craniotomy and the foramen magnum. The images were acquired in transversal, dorsal and sagittal planes. It was possible identified intracranial structures using ultrasound imaging through the temporal and parietal bones: brain, lateral ventricles, longitudinal fissure, some brain sulci, cerebellum, diencephalon and hippocampus. Ultrasound imaging of some structures through the craniotomy showed to be superior to ultrasound imaging through transosseous and computed tomography imaging. It was not possible to visualize the brain structures in ultrasound imaging through the frontal bone. Through the foramen magnum was observed only the cerebellum. Computed tomography imaging allow to visualize the brain tissue, lateral ventricles and osseous tentorium. Many other structures were identified based on the relationship to adjacent structures and their topography. It was concluded ultrasound imaging through temporal and lateral portion of parietal bones is avaluable radiologic technique. However, the images resoluation is inferior compared to the features obtained through the fontanelles or craniotomies. Computed tomography is an excellent radiologic technique. It produces sequential sections of the brain and it capable of discerning many different soft-tissues without superposition. However, some structures couldn\'t be directly visualize. The knowledge of anatomy of the brain is essential to avoid misinterpretation of the images.

Every scheduled treatment at a radiation therapy clinic involves a series of safety protocol to ensure the utmost patient care. Despite safety protocol, on a rare occasion an entirely preventable medical event, an accident, may occur. Delivering a treatment plan to the wrong patient is preventable, yet still is a clinically documented error. This research describes a computational method to identify patients with a novel machine learning technique to combat misadministration.The patient identification program stores face and fingerprint data for each patient. New, unlabeled data from those patients are categorized according to the library. The categorization of data by this face-fingerprint detector is accomplished with new machine learning algorithms based on Sparse Modeling that have already begun transforming the foundation of Computer Vision. Previous patient recognition software required special subroutines for faces and di↵erent tailored subroutines for fingerprints. In this research, the same exact model is used for both fingerprints and faces, without any additional subroutines and even without adjusting the two hyperparameters. Sparse modeling is a powerful tool, already shown utility in the areas of super-resolution, denoising, inpainting, demosaicing, and sub-nyquist sampling, i.e. compressed sensing. Sparse Modeling is possible because natural images are inherrently sparse in some bases, due to their inherrant structure. This research chooses datasets of face and fingerprint images to test the patient identification model. The model stores the images of each dataset as a basis (library). One image at a time is removed from the library, and is classified by a sparse code in terms of the remaining library. The Locally Competetive Algorithm, a truly neural inspired Artificial Neural Network, solves the computationally difficult task of finding the sparse code for the test image. The components of the sparse representation vector are summed by `1 pooling, and correct patient identification is consistently achieved 100% over 1000 trials, when either the face data or fingerprint data are implemented as a classification basis. The algorithm gets 100% classification when faces and fingerprints are concatenated into multimodal datasets. This suggests that 100% patient identification will be achievable in the clinal setting. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection