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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.
1

Image Processing as Applied to Medical Diagnostics

Thomas, Kristine A. 06 1900 (has links)
xi, 56 p. : ill. (some col.) A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / Image processing is a powerful tool for increasing the reliability and reproducibility of disease diagnostics. In the hands of pathologists, image processing provides quantitative data from histological images which supplement the qualitative data currently used by specialists. This thesis presents a novel method for analyzing digitized images of hematoxylin and eosin (H&E) stained histology slides to detect and quantify inflammatory polymorphonuclear leukocytes to aid in the grading of acute inflammation of the placenta as an example of the use of image processing in aid of diagnostics. Methods presented in this thesis include segmentation, a novel threshold selection technique and shape analysis. The most significant contribution is the automated color threshold selection algorithm for H&E stained histology slides which is the only unsupervised method published to date. / Committee in charge: Dr. John Conery, Chair; Dr. Matthew J. Sottile
2

Joint probability models of radiology images and clinical annotations

Arnold, Corey Wells. January 1900 (has links)
Thesis (Ph. D.)--UCLA, 2009. / Vita. Includes bibliographical references (leaves 135-149).
3

Estudo comparativo de métodos ultra-sonográficos de avaliação da idade gestacional em cadelas /

Castro, Viviane Montich de. January 2006 (has links)
Orientador: Maria Jaqueline Mamprim / Banca: Maria Denise Lopes / Banca: Franklin de Almeida Sterman / Resumo: A ultra-sonografia é um método de grande utilidade na Medicina Veterinária, apresentando grande valia no diagnóstico gestacional em cadelas, por ser um método precoce, acompanhar o desenvolvimento e a viabilidade embrionária e fetal. Entretanto possui algumas limitações para estimar a idade fetal, quando comparada com a Medicina Humana, principalmente devido a grande variação do porte nos cães. Foi realizado acompanhamento ultra-sonográfico em 27 cadelas prenhes de diferentes raças distribuídas em grupos segundo o peso corpóreo, com o objetivo de estudar a utilização do exame ultra-sonográfico como método de diagnóstico e acompanhamento gestacional, avaliando o desenvolvimento embrionário e fetal (organogênese), além de comparar os métodos de avaliação da idade gestacional e dias anteriores ao parto propostos por diversos autores, sendo utilizados para os cálculos as mensurações da vesícula embrionária, crânio, corpo e coração em três diferentes fases gestacionais, visando auxiliar o médico veterinário na escolha dos cálculos mais indicados para cada fase gestacional nos diferentes grupos de cadelas. / Abstract: Ultrasonography is a useful technique in veterinary medicine, showing high value in gestational diagnosis in bitches, because its use for early pregnancy detection as well as easiness to follow embrionary and fetal viability and development. However, as compared with human medicine, veterinary ultrasound technique has some limitations in estimating fetal age mainly because the high variation in size of dogs. Ultrasound accompaniments of 27 pregnant, all age and breed bitches separated in groups, were performed, with the objective of studying the ultrasound as a technique for gestational diagnosis and further observation, evaluating both embrionary and fetal development (organogenesis), and comparing previous evaluation techniques of gestational age on days before parturition proposed by different author. Mensurations of embryonic vesicles, skull, body size and heart at three different gestational stages were achieved, to help practitioners in choosing the most accurate estimation method at each gestational stage in different groups of bitches. / Mestre
4

Estudo prospectivo do diagnóstico por imagem em cães com ruptura do ligamento cruzado cranial. -

Oliveira, Rodrigo dos Reis. January 2006 (has links)
Orientador: Maria Jaqueline Mamprim / Banca: Lucy Mary / Banca: Ribeiro Muniz / Banca: Nilva Maria / Banca: Esteves Mascarenhaz / Resumo: exame radiográfico e a ultra-sonografia foram avaliados como técnicas de imagem no diagnóstico de ruptura do ligamento cruzado cranial (LCCr) em cães. Verificou-se sexo, raça, peso e idade dos animais atendidos no Hospital Veterinário (HV) da Faculdade de Medicina Veterinária e Zootecnia (FMVZ)-UNESP, Botucatu-SP. Num período de 12 meses, 31 cães com suspeita de ruptura do LCCr foram submetidos a exames radiográficos e ultra-sonográficos com objetivo de verificar sinais compatíveis com a lesão. Os casos positivos foram encaminhados para cirurgia, no intuito de confirmar o diagnóstico O e reparar a lesão. Foram verificados por meio de artrotomia 23 casos de ruptura total e dois casos de ruptura parcial do LCCr. Não houve diferença significativa entre machos e fêmeas, bem como entre animais inteiros ou castrados. Os cães sem raça definida foram os mais acometidos, seguidos pelo boxer, pit bull, pastor alemão e rottweiler. O animal mais leve pesava 8,4kg e o mais pesado 71kg, sendo a média igual a 27,9kg. Cães com peso igual ou inferior a 15kg apresentaram uma ocorrência menor da doença quando comparados aos animais com peso acima de 15,1kg. A faixa etária variou entre 12 meses a 13 anos, não sendo verificada variação considerável ao compararmos animais jovens e maduros. O exame radiográfico diagnosticou corretamente a lesão em 84% (21) dos casos, e quatro (16%) animais tiveram resultado falso-negativo. O exame ultra-sonográfico foi capaz de diagnosticar acertadamente 76% dos casos, e fornecer diagnóstico favorável nos 24% restantes, apresentando 100% de resultados positivos. No presente trabalho pudemos concluir que tanto o exame radiográfico quanto a ultra-sonografia são modalidades que podem contribuir de forma positiva no diagnóstico da ruptura do LCCr em cães. / Abstract: Radiographic and ultrasonographic examination was evaluated as image techniques in diagnostic of cranial cruciate ligament (CCL) rupture in dogs. Was determined the sex, breed, body weight and age of the animals taken care in the Hospital Veterinarian (HV) of the Faculdade de Medicina Veterinária e Zootecnia (FMVZ)-UNESP, Botucatu-SP. In a period of 12 months, 31 dogs with supposed CCL rupture were examined radiographic and ultrasonographically with objective to verify compatible signals with the injury. Positive cases had been directed for surgery, in intention to confirm the diagnostic and to repair the injury. Had been verified by artrotomy 23 cases of total rupture and two cases of partial rupture of the CCL. Did not have significant difference between males and females, as well as between intact or neutered animals. Mixed breeds had been affected, followed for boxer, pit bull, german shepherddog and rottweiler. The animal lightest weighed 8,4kg and the heaviest 71kg, mean body weight was 27,9kg. Dogs with equal or inferior weight 15kg had presented a lesser occurrence of the illness when compared with the animals with weight above of 15,1kg. Age varied enters 12 months and 13 years, without considerable variation between mature and young animals. Radiology correctly identified the injury in 84% of the cases, and four (16%) animals had false-negative resulted. In 76% of cases, ultrasonography correctly identified, and to supply to favorable diagnosis in 24% remains, presenting 100% of positive results. In the present study we could conclude that as radiology how ultrasonography are modalities diagnostics that can contribute of positive form in the diagnosis of the rupture of the CCL in dogs. / Mestre
5

Estudo comparativo de métodos ultra-sonográficos de avaliação da idade gestacional em cadelas

Castro, Viviane Montich de [UNESP] 23 November 2006 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:23:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-11-23Bitstream added on 2014-06-13T18:51:15Z : No. of bitstreams: 1 castro_vm_me_botfmvz.pdf: 1755900 bytes, checksum: 5100a483329bd5a759a4cf4b384957bb (MD5) / Universidade Estadual Paulista (UNESP) / A ultra-sonografia é um método de grande utilidade na Medicina Veterinária, apresentando grande valia no diagnóstico gestacional em cadelas, por ser um método precoce, acompanhar o desenvolvimento e a viabilidade embrionária e fetal. Entretanto possui algumas limitações para estimar a idade fetal, quando comparada com a Medicina Humana, principalmente devido a grande variação do porte nos cães. Foi realizado acompanhamento ultra-sonográfico em 27 cadelas prenhes de diferentes raças distribuídas em grupos segundo o peso corpóreo, com o objetivo de estudar a utilização do exame ultra-sonográfico como método de diagnóstico e acompanhamento gestacional, avaliando o desenvolvimento embrionário e fetal (organogênese), além de comparar os métodos de avaliação da idade gestacional e dias anteriores ao parto propostos por diversos autores, sendo utilizados para os cálculos as mensurações da vesícula embrionária, crânio, corpo e coração em três diferentes fases gestacionais, visando auxiliar o médico veterinário na escolha dos cálculos mais indicados para cada fase gestacional nos diferentes grupos de cadelas. / Ultrasonography is a useful technique in veterinary medicine, showing high value in gestational diagnosis in bitches, because its use for early pregnancy detection as well as easiness to follow embrionary and fetal viability and development. However, as compared with human medicine, veterinary ultrasound technique has some limitations in estimating fetal age mainly because the high variation in size of dogs. Ultrasound accompaniments of 27 pregnant, all age and breed bitches separated in groups, were performed, with the objective of studying the ultrasound as a technique for gestational diagnosis and further observation, evaluating both embrionary and fetal development (organogenesis), and comparing previous evaluation techniques of gestational age on days before parturition proposed by different author. Mensurations of embryonic vesicles, skull, body size and heart at three different gestational stages were achieved, to help practitioners in choosing the most accurate estimation method at each gestational stage in different groups of bitches.
6

Estudo prospectivo do diagnóstico por imagem em cães com ruptura do ligamento cruzado cranial. -

Oliveira, Rodrigo dos Reis [UNESP] 22 June 2006 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:23:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-06-22Bitstream added on 2014-06-13T19:09:54Z : No. of bitstreams: 1 oliveira_rr_me_botfmvz.pdf: 463745 bytes, checksum: e30c44492b4a15ddc8ea111cfcda01cf (MD5) / Universidade Estadual Paulista (UNESP) / exame radiográfico e a ultra-sonografia foram avaliados como técnicas de imagem no diagnóstico de ruptura do ligamento cruzado cranial (LCCr) em cães. Verificou-se sexo, raça, peso e idade dos animais atendidos no Hospital Veterinário (HV) da Faculdade de Medicina Veterinária e Zootecnia (FMVZ)-UNESP, Botucatu-SP. Num período de 12 meses, 31 cães com suspeita de ruptura do LCCr foram submetidos a exames radiográficos e ultra-sonográficos com objetivo de verificar sinais compatíveis com a lesão. Os casos positivos foram encaminhados para cirurgia, no intuito de confirmar o diagnóstico O e reparar a lesão. Foram verificados por meio de artrotomia 23 casos de ruptura total e dois casos de ruptura parcial do LCCr. Não houve diferença significativa entre machos e fêmeas, bem como entre animais inteiros ou castrados. Os cães sem raça definida foram os mais acometidos, seguidos pelo boxer, pit bull, pastor alemão e rottweiler. O animal mais leve pesava 8,4kg e o mais pesado 71kg, sendo a média igual a 27,9kg. Cães com peso igual ou inferior a 15kg apresentaram uma ocorrência menor da doença quando comparados aos animais com peso acima de 15,1kg. A faixa etária variou entre 12 meses a 13 anos, não sendo verificada variação considerável ao compararmos animais jovens e maduros. O exame radiográfico diagnosticou corretamente a lesão em 84% (21) dos casos, e quatro (16%) animais tiveram resultado falso-negativo. O exame ultra-sonográfico foi capaz de diagnosticar acertadamente 76% dos casos, e fornecer diagnóstico favorável nos 24% restantes, apresentando 100% de resultados positivos. No presente trabalho pudemos concluir que tanto o exame radiográfico quanto a ultra-sonografia são modalidades que podem contribuir de forma positiva no diagnóstico da ruptura do LCCr em cães. / Radiographic and ultrasonographic examination was evaluated as image techniques in diagnostic of cranial cruciate ligament (CCL) rupture in dogs. Was determined the sex, breed, body weight and age of the animals taken care in the Hospital Veterinarian (HV) of the Faculdade de Medicina Veterinária e Zootecnia (FMVZ)-UNESP, Botucatu-SP. In a period of 12 months, 31 dogs with supposed CCL rupture were examined radiographic and ultrasonographically with objective to verify compatible signals with the injury. Positive cases had been directed for surgery, in intention to confirm the diagnostic and to repair the injury. Had been verified by artrotomy 23 cases of total rupture and two cases of partial rupture of the CCL. Did not have significant difference between males and females, as well as between intact or neutered animals. Mixed breeds had been affected, followed for boxer, pit bull, german shepherddog and rottweiler. The animal lightest weighed 8,4kg and the heaviest 71kg, mean body weight was 27,9kg. Dogs with equal or inferior weight 15kg had presented a lesser occurrence of the illness when compared with the animals with weight above of 15,1kg. Age varied enters 12 months and 13 years, without considerable variation between mature and young animals. Radiology correctly identified the injury in 84% of the cases, and four (16%) animals had false-negative resulted. In 76% of cases, ultrasonography correctly identified, and to supply to favorable diagnosis in 24% remains, presenting 100% of positive results. In the present study we could conclude that as radiology how ultrasonography are modalities diagnostics that can contribute of positive form in the diagnosis of the rupture of the CCL in dogs.
7

Public health implications of medical diagnostic radiation exposure

Gerstenmaier, Jan Frank 02 1900 (has links)
Radiation from Computed Tomography (CT) is now the major contributor to population radiation dose. Despite controversy around the dose-effect relationship of radiation from CT, the linear non-threshold (LNT) theory is endorsed by many authorities, and constitutes the basis of cancer risk estimates. The purpose of this study was (1) a literature review of radiobiological theories, and methods of dose saving stategies in CT; (2) to highlight the importance of dose saving in CT, and to demonstrate how dose can be saved in a radiology department: Following a 40% reduction in reference X-ray tube current for a CT of the urinary tract, the effecitve dose and estimated lifetime attributable risk of incident cancer due to this CT in a group (n=103) were reduced by 37% and 38% in an age and sex-matched group respectively. The literature review showed that the public health implications of CT radiation exposure remain uncertain. / Health Studies / M.A. (Public Health)
8

UNDERSTANDING THE BIOLOGICAL EFFECTS AND CANCER RISK OF MEDICAL DIAGNOSTIC COMPUTED TOMOGRAPHY

Phan, Nghi 10 1900 (has links)
<p>The need to understand and accurately assess the health risks of low dose ionizing radiation is more important now than ever before. The global applications of ionizing radiation in medicine, mining, manufacturing, and the nuclear industry have increased exponentially in recent years. Parallel to this increase are the health concerns regarding occupational and medical exposures to radiation. The research presented here investigates the biological and health effects of ionizing radiation, specifically from medical diagnostic exposures.</p> <p>Medical diagnostic procedures such as x-rays and computed tomography (CT) scans account for a notable portion of the public's exposure to ionizing radiation. The health risk to humans associated with these low dose exposures is unknown. Often times they are correlated with risk estimates derived from much higher radiation doses. There is no doubt that very high dose ionizing radiation can be harmful; however, the same notion does not exist regarding exposures to low dose ionizing radiation such as that from medical diagnostic CT exposures.</p> <p>The objective of this research is to address the effects and risks associated with diagnostic CT scans. This research focuses on the biological outcome of cancer which remains a primary concern in health care and the development of radiation risk policies. The investigation utilized various mouse models that have differing sensitivities to radiation and susceptibilities to developing radiation-induced cancer.</p> <p>Results from this research found that low-dose diagnostic CT scans do not increase risk and can, in fact, induce protective effects. The hypothesis that harmful effects increase linearly with radiation dose is not supported by this research. With low doses of CT scans, protective biological effects such as reduced chromosomal aberrations, decreased radiation-induced oxidative DNA damage, and enhanced clearance of damaged cells have been observed. In cancer-prone mice, CT scans can increase longevity and reduce cancer risk by delaying the latency of specific cancers.</p> <p>This research advances the understanding of the biological effects and health risk associated with low-dose medical diagnostic procedures. This research is timely and important to allow medical practitioners, policy makers, and regulators to make informed decisions about using ionizing radiation in the clinic. Such knowledge is valuable as better, more complex, and perhaps more damaging modalities are being used to image and manage disease.</p> / Doctor of Philosophy (PhD)

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