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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

The impact of HIV infection when superimposed on pulmonary tuberculosis (either active or sequelae tuberculosis) on the success of bronchial artery embolisation.

Govind, Mayuri. January 2011 (has links)
ABSTRACT Pulmonary Tuberculosis (PTB) rates in Kwa Zulu Natal (KZN) is amongst the highest in the South Africa and is often associated with Human Immunodeficiency Virus (HIV) co-infection. Bronchial Artery Embolisation (BAE) is an expensive, time consuming procedure requiring operator skill and is accompanied by risk to both patient and operator. Aim: To investigate the impact of HIV infection when superimposed on PTB (active or sequelae) on the success of BAE. Method: A retrospective cross sectional study with descriptive and analytical components of the BAE procedure between January 2006 and December 2007 was performed on sequential BAE studies. These were analyzed for procedural and clinical outcome and reasons for procedural failure were investigated. The impact of CD4 level on procedural and clinical failure was investigated for a subset of cases. Cases were included if they presented with massive or life threatening haemoptysis with a diagnosis of previous or active PTB (made clinically, radiologically or microbiologically) in whom HIV status is known and where the clinician assessed a need for BAE, but excluded any third or more attempt at the procedure for that patient. Results: The final sample size after exclusion of 91 cases is 107. Each attempt at BAE was viewed as an individual case. The study population is made up of 74 HIV positive and 33 HIV negative cases. The median CD4 level is 176 cells / microlitre. Statistically, procedural success does not imply clinically successful outcome.HIV status does not correlate significantly with clinical or procedural results of BAE.CD4 level does not correlate significantly with clinical or procedural results of BAE. There is no technical reason of statistical significance that impacts on the success of the procedure when correlated with HIV status. These include being unable to select, unable to subselect, unable to engage securely, reflux, presence of fistulae and the presence of spinal feeder arteries. The complication rate is not statistically significant when correlated with HIV status. The differences in follow up of clinically unsuccessful cases were not significant when correlated with HIV status. On imaging, all cases demonstrated pathology. No particular zone is significant when correlated with HIV status. The most common finding is parenchymal architectural distortion followed closely by features of active tuberculous infection and no statistical significance is attributed to either when correlated with HIV status. The detection of lymphadenopathy is noted in 19.1% of HIV positive cases and 42.4% of HIV negative cases, and is the only feature of significance when correlated with HIV status. Interpretation: Coinfection with HIV does not have an impact on the success of BAE in patients with active or sequelae PTB who present with massive or life threatening haemoptysis. The rate of technical failure of the procedure suggests that this needs to be performed by persons that are adequately trained. Technical success does not imply clinical success but this finding was not statistically significant when correlated with HIV status. Re-evaluation of the procedure technique and improvements in local practice may produce results that correlate better with international standards. / Thesis (M.Med.)-University of KwaZulu-Natal, Durban, 2011.
12

Médecine futur antérieur ou les perspectives d'avenir inspirées par deux grandes découvertes scientifiques du XIXe siècle : la théorie microbienne et les rayons X /

Balcerowiak, Stéphane, January 1900 (has links)
Thesis (doctoral)--Université de Reims, 2003. / Title from Summary page ; description based on resource as of 2005-06-17. Includes bibliographical references and index.
13

A study of the methods of radiographic diagnosis of dental caries in epidemiological investigations

Haugejorden, Ola. January 1974 (has links)
Thesis--University of London. / At head of title: Community Dentistry Unit, The London Hospital Medical College Dental School. Includes bibliographical references (p. 248-269).
14

A study of the methods of radiographic diagnosis of dental caries in epidemiological investigations

Haugejorden, Ola. January 1974 (has links)
Thesis--University of London. / At head of title: Community Dentistry Unit, The London Hospital Medical College Dental School. Includes bibliographical references (p. 248-269).
15

Diagnostic radiography requests in Zimbabwe’s public hospital complex: completeness, accuracy and justtification

Sibanda, Lidion January 2012 (has links)
A thesis submitted in fulfilment of the requirements for the degree Master of Technology: Diagnostic Radiography in the Faculty of Health and Wellness Sciences at the Cape Peninsula University of Technology, 2012 / Complete, accurate and justified radiological examination requests are prerequisite to radiological exposures. However, global research shows evidence of high numbers of incomplete and inaccurate requests as well as that up to 77% radiological exposures are unjustified. Plain lumbar spine and plain skull radiology examinations are reported as being procedures that generate high dose and a low diagnostic yield. This study was designed to objectively measure the completeness, accuracy and justification of these two examinations in an effort to make inferences that will contribute to an improved radiology service. This research could therefore have positive effects on optimisation of radiation protection in Zimbabwe. Methodology A non participatory prospective descriptive analytical document review of quota sampled radiological request forms for 200 plain skull and 200 plain lumbar spine examinations was employed. Data was captured using structured data collection instruments designed and tested by the researcher for this study. The instrument was designed using the IAEA-HHS4 (2010) minimum prescribed request data as a framework and adding additional form fields found to be relevant through a review of all identified radiological request template forms in use at the research site. Data analysis involved central tendency measures and inferential statistics. Results: The central tendency demonstrated for the two examinations was that generally referrers for plain lumbar spine and for plain skull radiology would respectively provide 38.9 +/- 0.6% and 40.2+/-0.5% overall examination request information. This information was significantly below expectation. There was however no significant difference between the samples’ means for the two examinations. The tendency demonstrated in patient information for lumbar spine and skull requests was that generally referrers would respectively provide 48.4 +/- 0.8% and 49.5+/- 0.8% patient information. These values were inclusive of each other and they were significantly (p=0.00 Sig.) below expectation. There was however no significant difference between the two examinations’ data. The tendency demonstrated for examination information was that referrers for the research site would generally provide 29.8+/-0.8% (lumbar) and 32.6+/-0.8% (Skull) examination information. These values were significantly (p=0.000 Sig.) below expectation and demonstrated a significant difference between the sample means for the two examinations. With respect to referrer information, the tendency demonstrated was that generally referrers for plain lumbar spine and for plain skull examinations would respectively provide 38+/- 1% and 38.5 +/- 0.8% referrer identification information. These were significantly below expectation (p= 0.000 Sig.) but there was no significant difference between the samples’ means with respect to referrer information. With respect to accuracy of request data, it was observed that 5% plain lumbar spine and 3% plain skull requests were specific in so far as information documented on request forms could unambiguously identify the area to be imaged. It was also observed that 22.5% (lumbar spine) and 12% (skull) examination requests were indicated and therefore justified. All requests forms were found to be legible. Conclusions: Generally, referrers to this research site tend to provide incomplete, inaccurate and unjustified radiological request data. The observed levels of completeness, accuracy and justification of requests were generally consistent between the two examinations relative to expectation. These levels had medico-legal implications and negative effects on optimisation of radiation protection to patients. Further research to establish causes of this variance in referral behaviour is recommended. The researcher also recommends further research to establish whether there is an association between requested examination and completeness, accuracy and justification of diagnostic radiology examination requests. Keywords: Radiation protection, radiological request, complete request, accurate request, justified request, plain skull imaging, plain lumbar spine imaging.
16

Three-dimensional thinking in radiography

Venter, Dalene January 2008 (has links)
Dissertation submitted in fulfilment of the requirements for the degree Master of Technology: Radiography in the Faculty of Health and Wellness Sciences, 2008 / Introduction Research to date has not been able to agree whether spatial abilities can be developed by practice. According to some researchers spatial ability is an inherited cognitive ability, compared to spatial skills that are task specific and can be acquired through formal training. It is commonly assumed that radiographers require general cognitive spatial abilities to interpret complex radiographic images. This research was conducted to investigate second year radiography students’ three-dimensional thinking skills pertaining to film-viewing assessments. Materials and methods The experimental research strategy was mainly applied together with correlation research. Two trials were run (in 2005 and 2006). The sample group consisted of fifteen second year diagnostic radiography students in 2005 and twenty-three second year diagnostic radiography students, of the same institution, in 2006. Each year group was randomly divided into a control group and an intervention group. Two instruments were used, that is a film-viewing assessment and a three-dimensional test, Academic Aptitude Test (University) (AAT) nr. nine: Spatial Perception (3-D). The whole class completed this basic spatial aptitude test, as well as a base-line film viewing assessment, which focused on the evaluation of technique/anatomy of second year specialised radiographic projections. The marks that the students achieved in the fore-mentioned tests were compared, to determine if there was any correlation between their performances in the different tests. A curricular intervention, which was intended to improve applied three-dimensional skills, was subsequently applied. The students executed certain modified radiographic projections on parts of a human skeleton. For each radiographic projection, the students had to draw the relation of the X-ray beam to the specific anatomical structures, as well as the relation of these structures to the film. The related images of these projections were also drawn. With each of the following sessions, films including images of the previous session were discussed with each student. After the intervention, the whole class wrote a second film-viewing assessment. The marks achieved in this assessment were compared to the marks of the initial film-viewing assessment to determine the influence of the intervention on the performance of the intervention group. Following this assessment, for ethical reasons, the same intervention took place with the control group. A third film-viewing assessment was then written by all the diagnostic second year students to evaluate the overall impact of the intervention on the applied three-dimensional skills of the class. The marks of both the 2005 and 2006 classes (intervention classes) were compared to the marks achieved by former classes from 2000 to 2004 (control classes), in film-viewing assessments to evaluate the role of the curricular intervention over the years. The students again completed the three-dimensional test, Spatial Perception (3-D) to evaluate the impact of the intervention on students’ general three-dimensional cognitive abilities. These marks were also compared to the marks of the third filmviewing assessment, to determine if there was any correlation between the students’ performances in the different tests. Results The intervention groups did not perform significantly better in film-viewing assessments after the intervention, compared to the control groups, but reasonable differences, favouring the intervention group, were achieved. Statistical significance was achieved in film-viewing assessments with both year groups after the whole class had the intervention. The intervention year groups also performed significantly better than the previous year groups (without the intervention) in film-viewing assessments. The performance in general three-dimensional cognitive abilities of the group of 2006 improved significantly after the intervention, but on the contrary, the performance of the group of 2005 declined. There was a small intervention effect on the performance of the group of 2006. Only a weak to moderate correlation between the marks of the students achieved in the three-dimensional tests and the marks achieved in the film-viewing assessments, was found. Conclusion The contrasting evidence between the data of the two groups (2005 and 2006) in the three-dimensional tests and the small intervention effect on the performance of the group of 2006, makes the intervention not applicable for the increase of general spatial abilities. The results of this research show that the applied three-dimensional skills of radiography students in interpreting specialised and modified projections can be improved by intensive practice, independent of their inherited spatial abilities.
17

AN EVALUATION OF THE LEVEL OF SKILL REQUIRED OF OPERATORS OF A COMPUTER-ASSISTED RADIOLOGIC TOTAL LUNG CAPACITY MEASUREMENT SYSTEM (RELIABILITY, VALIDITY).

MAZZEO, JOHN., MAZZEO, JOHN. January 1985 (has links)
This research was conducted to obtain information regarding the feasibility of using non-medical personnel to obtain measurements of radiologic total lung capacity (TLC). Operators from each of four groups (general undergraduates, nursing students, medical students, radiologists) differing in the amount of medical training and/or experience reading x-rays, performed each of two tasks. The first task was the measurement of radiologic TLC for a set of twenty x-rays. The second task consisted of tracing the outline of the anatomical structures that must be identified in the execution of the radiologic TLC measurement task. Data from the radiologic TLC measurement task were used to identify possible group differences in the reliability and validity of the measures. The reliability analyses were performed within the framework of Generalizability Theory. While the results are not conclusive, due to small sample sizes, the analyses suggest that group differences in reliability of the measures, if they exist, are small. The concurrent validity of the measures was assessed by obtaining, for each experience level, the correlation between the group mean radiologic TLC for a film set and the TLC for that patient, obtained from a body plethysmograph. Only small differences in the group correlation coefficients were observed. A liberal test of these differences indicated they were not statistically significant. Additionally, two experience level by film sets ANOVAs were performed to determine possible group differences in how well the actual magnitudes of the radiologic TLC measures approximated those obtained with the body plethysmograph. These analyses indicated that the magnitude of the differences between radiologic and plethysmographic TLC measures were smaller for the undergraduates than for the nursing students and radiologists. Lastly, a number of analyses of the anatomical structure tracings were performed. Few interpretable group differences were found.
18

Avaliação de Kerma na superfície de entrada da pele em pacientes pediátricos do Hospital de Clínicas de Curitiba

Porto, Lorena Elaine 09 April 2010 (has links)
CAPES / No presente trabalho foram feitas medidas de dose recebida pelos pacientes pediátricos em exames de radiográficos de tórax em uma amostra de 386 exposições nas projeções AP/PA e Perfil. Os pacientes foram divididos em nas faixas etárias de 0-1 ano, 1-5 anos, 5-10 anos e 10-15 anos. Os exames foram realizados no Hospital de Clínicas da UFPR. Foi medida inicialmente a dose de entrada na pele com dosímetros termoluminescentes TLD-100 em uma amostra de 68 exposições, distribuídos pelas faixas etárias adotadas. A dose foi também determinada utilizando-se cálculos dosimétricos, que faz a determinação de dose para cada paciente a partir do rendimento do aparelho de raios X. O programa utiliza como dados de entrada a massa do paciente, a idade, a distância foco-pele, os dados da técnica radiográfica empregada (kV e mAs) e o valor de uma medida do rendimento feita com câmara de ionização para fins de calibração. Os primeiros dados avaliados mostraram doses maiores para os pacientes mais jovens. Uma mudança na técnica radiográfica dos exames contribuiu para a redução das doses. Foi avaliado todo o procedimento radiográfico e ficou caracterizada a necessidade de uma adequação da técnica radiográfica e uma constante otimização de todo o procedimento. Os dados foram colhidos novamente em 2007 e depois em 2009. Num primeiro momento os níveis de dose se mantiveram. Em 2009 os valores voltaram a subir devido ao aumento da carga (mAs). Os dados obtidos foram então comparados com os limites de dose permissíveis determinados pelos órgãos competentes. / In the present work absorbed doses by pediatric patients in chest radiographs were measured in 386 x-ray examinations in AP/PA and LAT projections. The patients were divided in age groups of 0-1 years, 1-5 years, 5-10 years and 10-15 years. The examinations were made at the pediatric room of Clinical Hospital of the Federal University of Paraná. Initially the entrance skin dose was measured with thermoluminescent dosimeters TLD-100 in 68 expositions, distributed in the age groups. The dose was also determined with the software dosimetric calculations that calculates the dose for each patient, from the X-ray equipment yield. The program uses the following data as input: patient mass, age, skin-focus, radiographic technique (kV, mAs), and the yield measurement made with an ionization chamber for calibration. The first evaluated data showed higher doses for the younger patients. A change in the radiographic technique of the examinations contributed to the reduction of the doses. The whole radiographic procedure was evaluated and, thus, showed that the radiographic technique had to be adjusted and the procedure as a whole had to be constantly optimized. Dates were measurement in 2007 again and after 2009. At a first moment the dose levels if had kept. In 2009 the values had come back to go up due to the increase of the load (mAs). The doses were then compared with the regulatory dose limits.
19

Avaliação de Kerma na superfície de entrada da pele em pacientes pediátricos do Hospital de Clínicas de Curitiba

Porto, Lorena Elaine 09 April 2010 (has links)
CAPES / No presente trabalho foram feitas medidas de dose recebida pelos pacientes pediátricos em exames de radiográficos de tórax em uma amostra de 386 exposições nas projeções AP/PA e Perfil. Os pacientes foram divididos em nas faixas etárias de 0-1 ano, 1-5 anos, 5-10 anos e 10-15 anos. Os exames foram realizados no Hospital de Clínicas da UFPR. Foi medida inicialmente a dose de entrada na pele com dosímetros termoluminescentes TLD-100 em uma amostra de 68 exposições, distribuídos pelas faixas etárias adotadas. A dose foi também determinada utilizando-se cálculos dosimétricos, que faz a determinação de dose para cada paciente a partir do rendimento do aparelho de raios X. O programa utiliza como dados de entrada a massa do paciente, a idade, a distância foco-pele, os dados da técnica radiográfica empregada (kV e mAs) e o valor de uma medida do rendimento feita com câmara de ionização para fins de calibração. Os primeiros dados avaliados mostraram doses maiores para os pacientes mais jovens. Uma mudança na técnica radiográfica dos exames contribuiu para a redução das doses. Foi avaliado todo o procedimento radiográfico e ficou caracterizada a necessidade de uma adequação da técnica radiográfica e uma constante otimização de todo o procedimento. Os dados foram colhidos novamente em 2007 e depois em 2009. Num primeiro momento os níveis de dose se mantiveram. Em 2009 os valores voltaram a subir devido ao aumento da carga (mAs). Os dados obtidos foram então comparados com os limites de dose permissíveis determinados pelos órgãos competentes. / In the present work absorbed doses by pediatric patients in chest radiographs were measured in 386 x-ray examinations in AP/PA and LAT projections. The patients were divided in age groups of 0-1 years, 1-5 years, 5-10 years and 10-15 years. The examinations were made at the pediatric room of Clinical Hospital of the Federal University of Paraná. Initially the entrance skin dose was measured with thermoluminescent dosimeters TLD-100 in 68 expositions, distributed in the age groups. The dose was also determined with the software dosimetric calculations that calculates the dose for each patient, from the X-ray equipment yield. The program uses the following data as input: patient mass, age, skin-focus, radiographic technique (kV, mAs), and the yield measurement made with an ionization chamber for calibration. The first evaluated data showed higher doses for the younger patients. A change in the radiographic technique of the examinations contributed to the reduction of the doses. The whole radiographic procedure was evaluated and, thus, showed that the radiographic technique had to be adjusted and the procedure as a whole had to be constantly optimized. Dates were measurement in 2007 again and after 2009. At a first moment the dose levels if had kept. In 2009 the values had come back to go up due to the increase of the load (mAs). The doses were then compared with the regulatory dose limits.
20

Réduction de la dose d'irradiation en tomodensitométrie de l'adulte

Tack, Denis 06 June 2005 (has links)
Le but de notre travail a été d’évaluer l’effet de la réduction de la dose d’irradiation en TDM multibarrette quant à la performance diagnostique, la confiance de l’observateur dans le diagnostic proposé, la capacité à suggérer un diagnostic alternatif dans quelques pathologies courantes et/ou caractérisées par des situations de faibles contrastes entre les structures anatomiques normales ou pathologiques. Nous avons donc comparé ces paramètres entre des TDM à doses réduites et à doses standard telles que couramment rapportées dans la littérature dans les circonstances suivantes :<p><p>•\ / Doctorat en sciences médicales / info:eu-repo/semantics/nonPublished

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