91 |
A computer-based cascaded modeling and experimental approach to the physical characterization of a clinical full-field mammography systemVed, Hetal R. January 2002 (has links)
Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: linear cascade model; screen-film; mammography. Includes bibliographical references (p. 64-71).
|
92 |
Validation and calibration of a digital subtraction radiography system for quantitative assessment of alveolar bone changesWoo, Mei-sum, Becky, January 2000 (has links)
Thesis (M.D.S.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves 69-85). Also available in print.
|
93 |
Radiography of the temporomandibular joint a comparison of information obtained from different radiographic techniques /Petersson, Arne. January 1900 (has links)
Thesis--University of Lund. / "English revised by Dr. Daniel P. Lipke." Includes bibliographical references (p. 20-24).
|
94 |
Digital intraoral radiography determination of technical properties and application evaluations /Mörner-Svalling, Ann-Catherine. January 2002 (has links)
Thesis (doctoral)--Karolinska Institutet, Stockholm, 2002. / Added t.p. with thesis statement inserted. Includes bibliographical references and index.
|
95 |
Radiography of the temporomandibular joint a comparison of information obtained from different radiographic techniques /Petersson, Arne. January 1900 (has links)
Thesis--University of Lund. / "English revised by Dr. Daniel P. Lipke." Includes bibliographical references (p. 20-24).
|
96 |
Avaliação entre o plano horizontal de Frankfurt osseo e cutaneo em diferentes raças e em diferentes padrões faciais / Evaluation between the Frankfurt horizontal plan cutaneous and osseous in different races and different facial patternCosta Neto, Mario Loureiro da 30 July 2007 (has links)
Orientador: Flavio Ricardo Manzi / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-09T09:51:56Z (GMT). No. of bitstreams: 1
CostaNeto_MarioLoureiroda_M.pdf: 700345 bytes, checksum: dfb1ff732ae92e8c062676ed1877997d (MD5)
Previous issue date: 2007 / Resumo: A radiografia cefalométrica lateral tem sido utilizada por grande parte dos profissionais da área odontológica e médica. Para a obtenção dessa radiografia, há a necessidade de orientação da cabeça do paciente, sendo o plano horizontal de Frankfurt (PHF) o mais utilizado pelos radiologistas. Dentre os fatores que levam os profissionais, especialmente os ortodontistas, a recusarem as radiografias cefalométricas é a orientação cefálica incorreta. As causas que levam a obtenção do posicionamento incorreto tem origens variadas, como a movimentação da cabeça do paciente e falhas por parte do operador. Sugeriuse que talvez o PHF ósseo não tem perfeita correspondência com o PHF cutâneo, proporcionando radiografias incorretas quanto ao posicionamento do paciente. Devido a esta hipótese, o objetivo deste trabalho foi avaliar a relação entre o PHF ósseo e o PHF cutâneo em diferentes raças e padrão facial. A amostra foi constituída de 27 indivíduos, os quais foram divididos em 3 grupos de acordo com a raça que pertenciam: 9 leucodermas, 9 melanodermas e 9 xantodermas. Em seguida, esta mesma amostra foi dividida de acordo com o grupo facial: 14 braquifaciais e 13 dolicofaciais. O método radiográfico foi o cefalométrico lateral, de acordo com a técnica preconizada por Broadbent em 1931 e foram obtidas fotografias de perfil, tendo como base à relação do PHF cutâneo com o plano horizontal. ... Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital / Abstract: Lateral cephalometric radiographies have been commonly used by health professionals. To obtain them, the patient's head should be adequately positioned, being the Frankfort horizontal plane (FHP) the most recommended and used by the Radiologists. Incorrect cephalic positioning is one of the factors that lead professionals, especially orthodontists, to reject such radiographies. This incorrect positioning might be related to the patient's head movement and/or errors made by the operator. Osseous FHP might not have a perfect correspondence with cutaneous FHP, leading professionals to judge the xray as unsatisfactory. Therefore, the aim of this study was to analyze the relationship between osseous FHP and cutaneous FHP (a line linking the superioredge of tragus to the inferioredge of eyeorbit), considering the cephalic variation among the different races, using the lateral cephalometric approach. The sample consisted of 27 individuals: 9 negroids, 9 caucasians, and 9 asians, being also assigned to two groups according to their facial pattern: 14 brachyfacial and 13 dolichofacial. Photographs were used to obtain cutaneous PHF. The lateralcephalometric Broadbent (1931) radiographic method was used in order to obtain the lateral photographs, using the relation of the cutaneous FHP and the horizontal plane. ... Note: The complete abstract is available with the full electronic digital thesis or dissertations / Mestrado / Radiologia Odontologica / Mestre em Radiologia Odontológica
|
97 |
Comparação entre imagens obtidas de telerradiografia lateral convencional, e imagens de tomografia computadorizada de feixe conico, na região da sinfise mentoniana / Comparing lateral teleradiography (LT) images with sagital section of cone-beam compued tomography (CBCT) in the mandibular shymphisys areaRodrigues, Messias 15 August 2018 (has links)
Orientador: Frab Norberto Boscolo / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-15T03:02:59Z (GMT). No. of bitstreams: 1
Rodrigues_Messias_M.pdf: 1187476 bytes, checksum: 1b1617668cea9154e821cbb731522fd3 (MD5)
Previous issue date: 2010 / Resumo: O objetivo com este estudo foi comparar imagens de Telerradiografia Lateral (TL) e de corte sagital mediano em Tomografia Computadorizada de Feixe Cônico (TCFC) pela exatidão da marcação de pontos na região de Sínfise Mandibular. A amostra com 28 TL e 28 TCFC, foi obtida de 28 pacientes submetidos a tratamento ortodôntico, os quais tinham características anatômicas semelhantes, na região de Sínfise Mandibular. Dez (10) examinadores calibrados analisaram todas as imagens, separadamente, em 2 períodos distintos, marcando seis pontos na região da Sínfise Mandibular, sendo eles: 1 - Ápice, 2 - Borda Incisal, 3 - Infradentário Lingual, 4 - Infradentário Vestibular, 5 - Mentoniano Interno, 6 - Mentoniano Externo. A definição dos pontos de referência, padrão prata, foi realizada por outro avaliador sem blindagem com as imagens, de TL e de TCFC, postas lado a lado. A distância, entre os pontos de referência e os marcados pelos avaliadores, foi mensurada com uma grade milimetrada superposta às imagens. Foi utilizado o coeficiente de correlação interclasses (CCI) para avaliar a reprodutibilidade intra- e inter-examinadores, e as distâncias entre os pontos marcados foram analisados pelo teste de Wilcoxon (a=0,05). Nos resultados observou-se que os pontos, Borda Incisal, Mentoniano Interno e Externo não apresentaram diferenças estatisticamente significativas (p>0,05) de distâncias entre as marcações, por outro lado os pontos Infradentário Vestibular e Lingual apresentaram diferenças (p<0,05). Baseado nos resultados obtidos pode-se concluir que a região da parte inferior da Sínfise Mandibular e Borda Incisal são locais que, para fins de diagnóstico, podem ser visualizados na TL com a mesma exatidão que a imagem tomográfica. Por outro lado, quando o local requisitado para diagnóstico estiver situado na altura mediana das raízes dos incisivos, tanto pela face vestibular quanto pela lingual, somente a imagem de TCFC oferece condições de visualização com exatidão das estruturas ali situadas. / Abstract: The aim with this study was to compare images of Lateral Teleradiography (LT) and sagittal section of Cone-Beam Computed Tomography (CBCT) through the exactness of landmarks made in the Mandibular Shymphisys region. The sample with 28 LT and 28 CBCT was obtained from 28 patients undergoing orthodontic treatment, which had similar anatomical features in the Mandibular Shymphisys region. 10 calibrated examiners evaluated all images, separately, in 2 distinct periods, marking six points in the Mandibular Shymphisys area, which are: 1 - Root Apex, 2 - Incisal Edge, 3 - Lingual Infradentale, 4 - Buccal Infradentale, 5 - Internal Mentum, 6 - External Mentum. Another examiner without blindness made the definition of factual landmarks, LT and CBCT, placed side by side. The distance between points (factual landmarks and those marked by the examiners) was measured with a millimeter grid superimposed to images. The interclass correlation coefficient (ICC) was used to evaluate the reliability intra- and inter-examiners, and the distance between marked points was analyzed using the Wilcoxon test (a=0.05). The results showed that statistical differences were not found in distances between Incisal Edge, in Internal Mentum and External Mentum points (p>0.05), on the other hand, Buccal Infradentale and Lingual Infradentale points were differences (p<0.05). In accordance with results, it can be concluded that the lower area of the Symphysis Mandibular and the Incisal Edge point are regions that to diagnosis finality can be visualized in the LT with the same exactness that in the CBCT. Therefore, when the region to diagnosis was the Symphysis Mandibular in middle region of incisor root, as much Buccal as Lingual faces, only the CBCT image supplied conditions to precise visualization of their anatomic structures. / Mestrado / Radiologia Odontologica / Mestre em Radiologia Odontológica
|
98 |
A comparative study of the 14C-Urea Breath Test and histology for the detection of Helicobacter pylori in terms of cost effectiveness and patient acceptabilityPeer, Fawzia Ismail January 2001 (has links)
Dissertation submitted in compliance with the requirements for the Masters Degree in Technology: Radiography, Technikon Natal, 2001. / The purpose of this study was to evaluate the Carbon-14 Urea Breath Test e4C-UBT) and histology for the detection of Helicobacter pylori (H pylori) in terms of cost-effectiveness and patient perceptions. It was hypothesized that the 14C_UBTwas more cost-effective and more easily tolerated than a histological analysis of a biopsy specimen obtained on endoscopy for H pylori detection / M
|
99 |
An exploration of factors potentially affecting the perception and interpretation of medical images used in higher educationOakley, Jason Nathaniel January 2010 (has links)
Much work is currently being undertaken to explore the impact of varying factors such as compression and image display parameters upon both measurable and perceived image quality in the clinical setting. However, little specific work was found that related to the effect of these factors within Higher Education, where high numbers of students, non-dedicated lecture theatres and a large number and variety of display devices results in many conditions that could impact upon the quality of digital radiographic images. Additionally, the College of Radiographers has identified (2006) that a radiographer comment accompanying radiographs may become a core competency. The aim of this thesis is to present and reflect upon a programme of research undertaken to explore which factors impacted upon students’ summary measures of performance and to begin to establish guidelines to ensure that images are presented optimally to the students, without creating unnecessary work for the academic staff. The effect of differing summary measures was also explored. A series of experiments were undertaken utilising volunteers from an undergraduate radiography programme. Research question The research question was: “What factors might potentially affect the perception and interpretation of medical images used in Higher Education?” Methods A series of six experiments were designed to evaluate the following factors: 1. The effect of compression upon diagnostic accuracy and perceived image quality; 2. The students’ perception of brightness and contrast changes of digital projectional radiographs and the effect of education upon this; 3. The ability of a detailed digital test image to discern limitations of a system; 4. The effect of image size, display device standardisation and image optimisation on summary measures of performance; 5. The ability of students to report consistently from digital test images; 6. The effect of differing marking criteria, confidence scales and summary measures of performance. Results This programme of research demonstrated that for digital projectional appendicular radiographs there was a significant difference between the levels of compression that observers preferred (p<0.05). However, there was no significant difference in accuracy for images reported uncompressed or at lossy levels of 40:1 (JPEG). Higher levels of compression were easily perceived, but low levels were not. It also confirmed other work established that low levels of compression were preferred by the human visual system due to the slight softening effect of the JPEG algorithm. Whilst individuals’ perception of brightness and contrast changes differed, the mean for groups of students was not significantly different and education did not have a significant effect. However, there was a significant difference (p<0.05) between those 30 and under and those over 30 in the level of perceived change, but not in the selection of the last acceptable image. A mid level grey background was shown to reduce perceived error of change compared to black or white backgrounds. Radar plots within this context are proposed as a way of identifying ideal images from students’ responses. Images corrected for the gamma of the system were identified as optimal by the cohorts. Images at 50% resolution stretched to 100%, the standardisation of display devices and image optimisation did not significantly affect student summary measures of performance. However this part of the study lacked power due to fewer participants than was initially anticipated. The summary measure of performance identified as optimal was the area under an AFROC curve, created from a five point category scale. This scale should be used by the observers to categorise their confidence and the marker to rate their confidence based upon the observers’ comments. This will allow a kappa value to be calculated that will give feedback on the level of conveyed confidence. Conclusions This programme of research has identified a number of factors that warrant more detailed research within the field of Higher Education. One is re-evaluating the effect of the year group on the quality factor proposed, as this research seems to indicate that education does have a positive effect on the reporting scores from a digital test image. In addition, there seems to be scope in considering the radar plot as a method of identifying where the ideal image lies. A range of minimum standards, as proven by these experiments and taken from literature, are proposed as the best practice for lecture presentation and assessment. Recommendations are made for further research into the effect of several parameters where power was low. This research has established some of the ground rules for improving the display and assessment of medical images in Higher Education.
|
100 |
A skills gap analysis of radiographers in management positionsBurchell, Catherine Ann 10 May 2012 (has links)
M.Tech. / To ensure that effective management development and training is incorporated in managerial training programmes, it is imperative that an analysis is undertaken to ascertain what skill gaps exist. The aim of the study was to survey the management expertise of Radiographers in management positions. Reference was made to identify specific skill gaps, and skill gap opportunities. The study also intended to determine whether specific trends existed in certain sectors of the public, private and mining health sector. The first part of the study consisted of a postal questionnaire. A total of two hundred and fifteen Radiographers in management positions from the public, private and mining hospitals in the Gauteng, Limpopo and Mpumalanga regions of South Africa were chosen for the study. The sample population was then contacted telephonically before the postal questionnaire commenced. An outline of what the research entailed was explained to each participant. The results were statistically analysed from a total of sixty-three technically correct questionnaires received. The findings were summarised by means of using descriptive statistics. Statistical analysis of the received data validated that management, interpersonal and leadership skills were shown to be lacking in all three sectors. These skills, according to all of the three sectors, required both reinforcing and developing. Skills of least importance which did not require reinforcing or developing included work roster strategy, recruitment strategy and tendering skills. The results obtained from the postal questionnaire were re-tested by means of a structured interview involving thirty Radiographers in management positions from the same regions to that of the postal questionnaire. Once the data had been compiled, descriptive statistics were again employed to summarise the findings. Participants expressed an interest in developing managerial skills relating to laws and regulations, conflict resolution, interpersonal skills and financial management. The findings of the research supported and acknowledged that, in order for competent managers and leaders to be trained and developed in the field of Radiography, a planned and purposeful approach should be adopted where skills gaps are analysed and focused upon.
|
Page generated in 0.0535 seconds