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1
簡適悠 and Sik-yau Anita Kan. "A clinical audit of mammography screening." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B41710113.
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Yakoubian, Jeffrey Scott. "Adaptive histogram equalization for mammographic image processing." Thesis, Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/16387.
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Brooks, Kenneth W. "Automated analysis of mammography phantom images." Diss., Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/17900.
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Peng, Jinghong P. "Automated acceptance criteria for the American College of Radiology (ACR) mammographic accreditation phantom images." Thesis, Georgia Institute of Technology, 1991. http://hdl.handle.net/1853/18248.
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Napolitano, Mary Elizabeth. "Mammographic x-ray unit peak kilovoltage and spectral quality determination using film densitometry." Diss., Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/15840.
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Khan, Fyzodeen. "Detection of masses in x-ray mammograms /." View online ; access limited to URI, 2003. http://0-wwwlib.umi.com.helin.uri.edu/dissertations/dlnow/3103706.
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Ved, Hetal R. "A computer-based cascaded modeling and experimental approach to the physical characterization of a clinical full-field mammography system." Link to electronic thesis, 2002. http://www.wpi.edu/Pubs/ETD/Available/etd-0920102-144012.
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Cheok, Frida. "Participation in mammographic screenings in South Australia /." Title page, contents and abstract only, 1998. http://web4.library.adelaide.edu.au/theses/09PH/09phc51843.pdf.
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Cerneaz, Nicholas J. "Model-based analysis of mammograms." Thesis, University of Oxford, 1994. http://ora.ox.ac.uk/objects/uuid:a8d91bb2-429c-4da3-9f1b-6209771c61b5.
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Metastasised breast cancer kills. There is no known cure, there are no known preventative measures, there are no drugs available with proven capacity to abate its effects. Early identification and excision of a malignancy prior to metastasis is the only method currently available for reducing the mortality due to breast disease. Automated analysis of mammograms has been proposed as a tool to aid radiologists detect breast disease earlier and with greater efficiency and success. This thesis addresses some of the major difficulties associated with the automated analysis of mammograms, in particular the difficulties caused by the high-frequency, relatively insignificant curvi-linear structures (CLS) comprising the blood vessels, milk-ducts and fibrous tissues. Previous attempts at automation have been overlooked these structures and the resultant complexity of that oversight has been handled inappropriately. We develop a model-based analysis of the CLS features, from the very anatomy of the breast, through mammography and digitisation to the image intensities. The model immediately dictates an algorithm for extracting a high-level feature description of the CLS features. This high-level feature description allows a systematic treatment of these image features prior to searching for instances of breast disease. We demonstrate a procedure for implementing such prior treatment by 'removing' the CLS features from the images. Furthermore, we develop a model of the expected appearance of mammographic densities in the CLS-removed image, which leads directly to an algorithm for their identification. Unfortunately the model also extracts many regions of the image that are not significant mammographic densities, and this therefore requires a subsequent segmentation stage. Unlike previous attempts which apply neural networks to this task, and therefore incorporate inherent insignificance as a consequence of insufficient data availability describing the significant mammographic densities, we illustrate the application of a new statistical method (novelty analysis) for achieving a statistically significant segmentation of the mammographic densities from the plethora of candidates identified at the previous stage. We demonstrate the ability of the CLS feature description to identify instances of radial-scar in mammograms, and note the suitability of the CLS and density descriptions for assessment of bilateral and temporal asymmetry. Some additional potential applications of these feature descriptions in arenas other than mammogram analysis are also noted.
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Coakley, Kerry Shona. "Phase contrast mammography." Thesis, Queensland University of Technology, 2000.
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Broyden, Robert R. "Breast cancer early detection : a test using hairstylists to promote mammography among women at risk /." Thesis, This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-03122009-040613/.
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Pettit, Elaine J. (Elaine Joyce). "Synthesis of 2-D Images From the Wigner Distribution with Applications to Mammography and Edge Extraction." Thesis, University of North Texas, 1995. https://digital.library.unt.edu/ark:/67531/metadc332685/.
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A new method for the general application of quadratic spatial/spatial frequency domain filtering to imagery is presented in this dissertation. The major contribution of this research is the development of an original algorithm for approximating the inverse psuedo Wigner distribution through synthesis of an image in the spatial domain which approximates the result of filtering an original image in the DPWD domain.
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Daniels, Tasneem. "Bi-rads final assessment categories in breast cancer patients." Thesis, Cape Peninsula University of Technology, 2019. http://hdl.handle.net/20.500.11838/2969.
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Thesis (MSc (Radiography))--Cape Peninsula University of Technology, 2019INTRODUCTION: The Breast Imaging Reporting and Data System (BI-RADS) was developed by the American College of Radiology (ACR). The BI-RADS is an internationally accepted method of assessing and reporting on mammograms and breast ultrasound images. The BI-RADS consists of a lexicon (descriptors) and assessment categories. The ACR aimed to standardise mammography reporting and placing the findings in the appropriate assessment category. The aim of this study was to establish the accuracy of the BI-RADS assessment categories for mammography and breast ultrasound images in women diagnosed with breast cancer. METHOD: Data were retrieved from 77 patients who were diagnosed with breast cancer from 1 January 2013 to 31 December 2014. Seven did not meet the inclusion criteria and were excluded. The study sample size was 70 (n=70) patients. All mammography reports included a BI-RADS assessment category of all patients diagnosed with breast cancer within the study period. These reports were analysed and compared with histopathology results. The BI-RADS assessment category and descriptors were collected from the mammogram reports; the histopathology report indicated the type of breast cancer. All reports were obtained from the patients' folders at the research site. In addition, questionnaires were distributed among radiologists to assess whether their experience and training had an influence on the accuracy of reporting in the BI-RADS assessment categories. Descriptive and inferential statistical analysis was used for data analysis. RESULTS: The most common malignancy diagnosed was invasive ductal carcinoma with a total of 70% (n=54), followed by ductal carcinoma in situ with 10.4% (n=8) and invasive lobular carcinoma with 9.1% (n=7). The histology results confirmed breast cancer for all BI-RADS 4 and 5 assessment categories. The mammogram was able to detect 93.5% of abnormalities and breast ultrasound 84.4% of abnormalities in this study sample. Breast ultrasound was used as an adjunct to mammography and hence an overall combined diagnostic rate was 100%. Mammography descriptors: The more common malignancy findings were spiculated mass margin, 35.1% (n=27). Ultrasound descriptors: The more common malignancy findings were hypoechoic echo pattern, 55.8% (n=43). There was no significant association (p=0.152) between the radiologists' years of experience and BI-RADS 3, 4 and 5 assessment category reporting. Of the 15 responses, 67% agreed that the BI-RADS standardises breast imaging reporting and reduces confusion, 33% agreed that the BI-RADS allows better communication between radiologists and referring physicians, and 40% agreed that the BI-RADS clarifies further management for patients by helping to stratify risk management. CONCLUSION: The outcome of this study indicated that the use of BI-RADS assessment categories is useful for predicting the likelihood of malignancy when used correctly. The outcome of BI-RADS 4 and BI-RADS 5 had a positive predictive value of 100%, which corresponded well with histology results. The descriptor findings suggested that spiculated mass margins, irregular-shaped masses, hypoechoic echo pattern and posterior shadowing were high predictors of malignancy and warranted a placement in the BI-RADS 5 assessment category.
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Al-Roubaie, Zahra. "Human breast images : segmentation, analysis and conversion to electrical parameter profiles for Semcad-X electromagnetic simulator." Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=116044.
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Electrical parameter profiles of human breast images can be used to simulate and analyze the anticipated effects on tissue from its interaction with electromagnetic fields involved in the cancer treatment exposure. In part, the success of this approach depends on the accuracy and precision in identifying the different tissue types. In this work, we propose two methods of segmenting human breast images with malignant tumors. The first method of algorithmic partitioning of the image involves manual color-edge contouring of the tissues using a cursor and subsequent identification of the tissue types. For the second method, MRI T1 values and thresholds are used to perform segmentation and we investigate the potential of incorporating edge detection. The first method is effective, while the second lacks precision, but eliminates the need of manual contouring. The images are imported as BMP files into SEMCAD, an electromagnetic simulation tool based on finite-difference time-domain method, which recognizes the grouped tissues and creates a model of the image. The model allows the user to easily assign electrical parameter values to the grouped tissues, according to the measured values reported in the literature.
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Wen, Yiding. "Detecting microcalcifications in digitised mammograms by a computer aided diagnostic system." Thesis, The University of Sydney, 1999. https://hdl.handle.net/2123/27591.
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Breast cancer is now one of the most common forms of cancer and the leading cause of
mortality in women in the developed countries. Early detection of breast cancer is
currently the way to reduce breast cancer mortality and enhance the cure rate.
Mammogram screening is widely recognized as the most reliable method for early
detection of lesions and clustered microcalcifications, which are the two prominent
symptoms of breast cancer. This thesis presents an image processing procedure for the
automatic detection of clustered microcalcifications in digitized mammograms.
This method consists of two main steps. First, possible microcalcification pixels in the
mammograms are segmented out using wavelet features, and grouped into potential
individual microcalcification objects by their spatial connectivity. Second, individual
microcalcifications are detected by using the structure features extracted from the
potential microcalcification objects. The classifiers used in the two steps are feedforward
neural networks. The method is applied to 40 regions of interest extracted from
mammograms in the Nijimegen database containing 144 clusters of microcalcifications.
Results show that the proposed procedure gives satisfactory detection performance. In
particular, a 97 percent mean true positive detection rate is achieved at the cost of 1.67
false positive in the whole dataset.
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Masek, Martin. "Hierarchical segmentation of mammograms based on pixel intensity." University of Western Australia. School of Electrical, Electronic and Computer Engineering, 2004. http://theses.library.uwa.edu.au/adt-WU2003.0033.
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Mammography is currently used to screen women in targeted risk classes for breast cancer. Computer assisted diagnosis of mammograms attempts to lower the workload on radiologists by either automating some of their tasks or acting as a second reader. The task of mammogram segmentation based on pixel intensity is addressed in this thesis. The mammographic process leads to images where intensity in the image is related to the composition of tissue in the breast; it is therefore possible to segment a mammogram into several regions using a combination of global thresholds, local thresholds and higher-level information based on the intensity histogram. A hierarchical view is taken of the segmentation process, with a series of steps that feed into each other. Methods are presented for segmentation of: 1. image background regions; 2. skin-air interface; 3. pectoral muscle; and 4. segmentation of the database by classification of mammograms into tissue types and determining a similarity measure between mammograms. All methods are automatic. After a detailed analysis of minimum cross-entropy thresholding, multi-level thresholding is used to segment the main breast tissue from the background. Scanning artefacts and high intensity noise are separated from the breast tissue using binary image operations, rectangular labels are identified from the binary image by their shape, the Radon transform is used to locate the edges of tape artefacts, and a filter is used to locate vertical running roller scratching. Orientation of the image is determined using the shape of the breast and properties of the breast tissue near the breast edge. Unlike most existing orientation algorithms, which only distinguish between left facing or right facing breasts, the algorithm developed determines orientation for images flipped upside down or rotated onto their side and works successfully on all images of the testing database. Orientation is an integral part of the segmentation process, as skin-air interface and pectoral muscle extraction rely on it. A novel way to view the skin-line on the mammogram is as two sets of functions, one set with the x-axis along the rows, and the other with the x-axis along the columns. Using this view, a local thresholding algorithm, and a more sophisticated optimisation based algorithm are presented. Using fitted polynomials along the skin-air interface, the error between polynomial and breast boundary extracted by a threshold is minimised by optimising the threshold and the degree of the polynomial. The final fitted line exhibits the inherent smoothness of the polynomial and provides a more accurate estimate of the skin-line when compared to another established technique. The edge of the pectoral muscle is a boundary between two relatively homogenous regions. A new algorithm is developed to obtain a threshold to separate adjacent regions distinguishable by intensity. Taking several local windows containing different proportions of the two regions, the threshold is found by examining the behaviour of either the median intensity or a modified cross-entropy intensity as the proportion changes. Image orientation is used to anchor the window corner in the pectoral muscle corner of the image and straight-line fitting is used to generate a more accurate result from the final threshold. An algorithm is also presented to evaluate the accuracy of different pectoral edge estimates. Identification of the image background and the pectoral muscle allows the breast tissue to be isolated in the mammogram. The density and pattern of the breast tissue is correlated with 1. Breast cancer risk, and 2. Difficulty of reading for the radiologist. Computerised density assessment methods have in the past been feature-based, a number of features extracted from the tissue or its histogram and used as input into a classifier. Here, histogram distance measures have been used to classify mammograms into density types, and ii also to order the image database according to image similarity. The advantage of histogram distance measures is that they are less reliant on the accuracy of segmentation and the quality of extracted features, as the whole histogram is used to determine distance, rather than quantifying it into a set of features. Existing histogram distance measures have been applied, and a new histogram distance presented, showing higher accuracy than other such measures, and also better performance than an established feature-based technique.
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Ball, John E. "Three stage level set segmentation of mass core, periphery, and spiculations for automated image analysis of digital mammograms." Diss., Mississippi State : Mississippi State University, 2007. http://sun.library.msstate.edu/ETD-db/ETD-browse/browse.
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Kwok, Sze Man Simon. "Attribute-driven segmentation and analysis of mammograms." University of Western Australia. Centre for Intelligent Information Processing Systems, 2005. http://theses.library.uwa.edu.au/adt-WU2005.0010.
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[Truncated abstract] In this thesis, we introduce a mammogram analysis system developed for the automatic segmentation and analysis of mammograms. This original system has been designed to aid radiologists to detect breast cancer on mammograms. The system embodies attribute-driven segmentation in which the attributes of an image are extracted progressively in a step-by-step, hierarchical fashion. Global, low-level attributes obtained in the early stages are used to derive local, high-level attributes in later stages, leading to increasing refinement and accuracy in image segmentation and analysis. The proposed system can be characterized as: • a bootstrap engine driven by the attributes of the images; • a solid framework supporting the process of hierarchical segmentation; • a universal platform for the development and integration of segmentation and analysis techniques; and • an extensible database in which knowledge about the image is accumulated. Central to this system are three major components: 1. a series of applications for attribute acquisition; 2. a standard format for attribute normalization; and 3. a database for attribute storage and data exchange between applications. The first step of the automatic process is to segment the mammogram hierarchically into several distinctive regions that represent the anatomy of the breast. The adequacy and quality of the mammogram are then assessed using the anatomical features obtained from segmentation. Further image analysis, such as breast density classification and lesion detection, may then be carried out inside the breast region. Several domain-specific algorithms have therefore been developed for the attribute acquisition component in the system. These include: 1. automatic pectoral muscle segmentation; 2. adequacy assessment of positioning and exposure; and 3. contrast enhancement of mass lesions. An adaptive algorithm is described for automatic segmentation of the pectoral muscle on mammograms of mediolateral oblique (MLO) views
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Sechopoulos, Ioannis. "Investigation of physical processes in digital x-ray tomosynthesis imaging of the breast." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/22589.
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Beckett, Jonathan. "Studies of benefit and risk resulting from the UK Breast Screening Programme." Thesis, University of Newcastle Upon Tyne, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.364812.
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Turnbull, Deborah Anne. "Psychosocial issues in implementing mammography screening in Australia." Phd thesis, Faculty of Arts, 1992. http://hdl.handle.net/2123/8575.
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Alvarez, Matheus. "Otimização de imagens de mamografia computadorizada /." Botucatu, 2012. http://hdl.handle.net/11449/97998.
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Orientador: José Ricardo de Arruda MirandaCoorientador: Diana Rodrigues de Pina
Banca: Sérgio José Barbosa Duarte
Banca: André Petean Trindade
Resumo: O propósito deste trabalho é apresentar uma metodologia de análise computacional de radiografias do fantoma de acreditação mamográfico (FAM) do colégio americano de radiologia (CAR) a ser utilizado em serviços de mamografia. Processamentos via transformada discreta de wavelet (TDW) são usados de maneira a realçar o contraste dos objetos teste a serem analisados, possibilitando condições automáticas da avaliação do desempenho de sistemas mamográficos. Os algoritmos desenvolvidos localizam a região do fantoma na radiografia de maneira totalmente automatizada, onde são aplicados processamentos via TDW, que realçam características geométricas e morfológicas do fantoma. Cada região da imagem é submetida a testes de reconhecimento de detalhes estruturais, visando a minimização de detecção de falsos positivos. Em seguida, parâmetros morfológicos e geométricos das imagens processadas são utilizados na quantificação do nível de qualidade final da imagem. Também foram investigados as possibilidades de otimizar a dose utilizada na obtenção de mamografias e o potencial de otimização dos algoritmos desenvolvidos. A análise das tabelas de contingência revelou uma associação significativa ( p < 0.001 ) para as avaliações de massas, fibras e microcalcificações, revelando um grau de concordância satisfatório entre algoritmos e radiologistas. As médias das diferenças para simuladores de massas, fibras e microcalcificações obtidas foram, respectivamente, -0,11±0,86, -0,01±0,82 e 0,14±0,88. Foi avaliado o potencial de diminuição de dose na obtenção da mamografia de uma mama padrão e um potencial de redução de dose de aproximadamente 50% da dose utilizada atualmente foi encontrado. A metodologia desenvolvida e validada pode ser utilizada na detecção de pequenas variações da... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The purpose of this paper is to present a methodology for computed analysis of the mammographic accreditation phantom (MAP) recommended by the American College of Radiology (ACR) radiographs. Wavelet enhancement by the discrete wavelet transform (DWT) are used in order to highlight the test objects to be analyzed. Enabling automatic conditions of evaluating the performance of mammographic systems. The algorithms presented here locate the region of the ACR MAP in the radiograph by a fully automatic process. DWT is used to enhance the contrast between the objects and the background this allows morphological operator to detect the test objects in each region. Then, Morphological and geometrical pparameters of the processed images are used to quantify the final level of image quality presented by the system. We also investigated the possibilities of optimizing the dose used in the acquisition of mammograms. Our analysis revealed a strong correlation (p<0.001) in the computed evaluation of the test objects and radiologists scores.The mean difference between the human and the computed score were -0.11±0.86, -0.01±0.82, 0.14±0.88. We have found a potential of dose reduction in approximated 50% of the currently radiation level without prejudicing the image quality level. The methodology were developed and validated to show that they can be used to detect small variations in the radiographs levels. Our... (Complete abstract click electronic access below)
Mestre
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Scherl-Slusher, Alice I. "Screening Mamography: A Comparison Between US and Australian Healthcare Delivery." Youngstown State University / OhioLINK, 2000. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1007583885.
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Parham, Christopher Allen Pisano Etta D. "System parameters and performance specifications for the application of Diffraction Enhanced Imaging and Multiple Image Radiography to breast imaging." Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2006. http://dc.lib.unc.edu/u?/etd,294.
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Thesis (Ph. D.)--University of North Carolina at Chapel Hill, 2006.Title from electronic title page (viewed Oct. 10, 2007). "... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Biomedical Engineering." Discipline: Biomedical Engineering; Department/School: Medicine.
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Alvarez, Matheus [UNESP]. "Otimização de imagens de mamografia computadorizada." Universidade Estadual Paulista (UNESP), 2012. http://hdl.handle.net/11449/97998.
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O propósito deste trabalho é apresentar uma metodologia de análise computacional de radiografias do fantoma de acreditação mamográfico (FAM) do colégio americano de radiologia (CAR) a ser utilizado em serviços de mamografia. Processamentos via transformada discreta de wavelet (TDW) são usados de maneira a realçar o contraste dos objetos teste a serem analisados, possibilitando condições automáticas da avaliação do desempenho de sistemas mamográficos. Os algoritmos desenvolvidos localizam a região do fantoma na radiografia de maneira totalmente automatizada, onde são aplicados processamentos via TDW, que realçam características geométricas e morfológicas do fantoma. Cada região da imagem é submetida a testes de reconhecimento de detalhes estruturais, visando a minimização de detecção de falsos positivos. Em seguida, parâmetros morfológicos e geométricos das imagens processadas são utilizados na quantificação do nível de qualidade final da imagem. Também foram investigados as possibilidades de otimizar a dose utilizada na obtenção de mamografias e o potencial de otimização dos algoritmos desenvolvidos. A análise das tabelas de contingência revelou uma associação significativa ( p < 0.001 ) para as avaliações de massas, fibras e microcalcificações, revelando um grau de concordância satisfatório entre algoritmos e radiologistas. As médias das diferenças para simuladores de massas, fibras e microcalcificações obtidas foram, respectivamente, -0,11±0,86, -0,01±0,82 e 0,14±0,88. Foi avaliado o potencial de diminuição de dose na obtenção da mamografia de uma mama padrão e um potencial de redução de dose de aproximadamente 50% da dose utilizada atualmente foi encontrado. A metodologia desenvolvida e validada pode ser utilizada na detecção de pequenas variações da...
The purpose of this paper is to present a methodology for computed analysis of the mammographic accreditation phantom (MAP) recommended by the American College of Radiology (ACR) radiographs. Wavelet enhancement by the discrete wavelet transform (DWT) are used in order to highlight the test objects to be analyzed. Enabling automatic conditions of evaluating the performance of mammographic systems. The algorithms presented here locate the region of the ACR MAP in the radiograph by a fully automatic process. DWT is used to enhance the contrast between the objects and the background this allows morphological operator to detect the test objects in each region. Then, Morphological and geometrical pparameters of the processed images are used to quantify the final level of image quality presented by the system. We also investigated the possibilities of optimizing the dose used in the acquisition of mammograms. Our analysis revealed a strong correlation (p<0.001) in the computed evaluation of the test objects and radiologists scores.The mean difference between the human and the computed score were -0.11±0.86, -0.01±0.82, 0.14±0.88. We have found a potential of dose reduction in approximated 50% of the currently radiation level without prejudicing the image quality level. The methodology were developed and validated to show that they can be used to detect small variations in the radiographs levels. Our... (Complete abstract click electronic access below)
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Amer, Heba [Verfasser]. "Specimen radiography: digital breast tomosynthesis versus full field digital mammography : which modality provides more accurate prediction of margin status? / Heba Amer." Berlin : Medizinische Fakultät Charité - Universitätsmedizin Berlin, 2019. http://d-nb.info/1202045014/34.
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Mardegan, José Renato Linares 1984. "Aplicações da radiografia por contraste de fase em tecidos de mama in vitro." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/277537.
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Orientador: Carlos Manuel Giles Antunez de MayoloDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin
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Resuno: Esta dissertação de mestrado teve por objetivo a realização de imagens pela técnica de imagens por contraste de fase utilizando o método de imagens realçadas por difração (IRD) para analisar amostras histológicas de mama in vitro. Os sistemas para produção das IRD foram desenvolvidos utilizando um gerador convencional no Laboratório de Cristalografia Aplicada e Raios X (LCARX - UNICAMP) e também com radiação síncrotron no Laboratório Nacional de Luz Síncrotron (XRD2 - LNLS). As amostras estudadas foram corpos de provas, um inseto e tecidos de mama com carcinoma lobular invasivo e carcinoma ductal invasivo fornecidas pelo Centro de Atenção Integral a Saúde da Mulher (CAISM - UNICAMP). As imagens foram realizadas pelo método convencional e também pelo método de IRD. As imagens realçadas por difração de corpos de prova, do inseto e dos tecidos com câncer de mama mostraram resolução superior ao comparadas com imagens convencionais principalmente das interfaces entre tecidos em uma amostra, o que resulta em um diagnostico mais preciso do paciente. As imagens obtidas pelo método IRD apresentam contraste, visibilidade e razão-sinal ruído muito superiores quando comparados com as imagens obtidas pela técnica convencional de absorção. A imagem obtida do tecido com carcinoma lobular invasivo apresentou maiores detalhes ao compará-la com a imagem convencional porém não foi possível visualizar precisamente as bordas do tumor. As imagens realçadas por difração têm qualidade superior devido à utilização de um cristal analisador colocado após a amostra. Este cristal funciona como uma estreita fenda angular resultando em imagens com ganho de contraste em relação às imagens pelos métodos convencionais. Utilizando o algoritmo de tratamento das IRD foram obtidas as imagens de Absorção Aparente e Refração ajustando o cristal analisador em diferentes posições da curva de difração e não apenas na posição de meia altura da curva de refletividade. A escolha de diferentes posições da curva mostrou que as imagens de absorção aparente, refração e as imagens obtidas nestes flancos ganham em resolução quando ajustadas para posições distantes do topo. Valores calculados para os parâmetros sinal ruído borda e visibilidade em imagens obtidas em posições distantes do topo chegaram a ser cerca de dez vezes maiores que nas imagens convencionais para as amostras de corpos de prova. Isto ocorre porque o cristal analisador está selecionando diferentes feixes refratados na amostra.
Abstract: In this dissertation we have produced in vitro breast images by a phase contrast imaging technique using the diffraction enhanced imaging (DEI) method. The DEI setup was implemented both at the X-ray applied Crystallography Laboratory (LCARX) using a conventional generator and at the XRD2 beamline of the Brazilian National Synchrotron Light Laboratory (LNLS) in Campinas. Two types of breast cancer were investigated from breast tissues provided by the University Center for Women Health (CAISM-UNICAMP) through collaboration with a professional mastologist: invasive lobular carcinoma and invasive ductal carcinoma. Other images were performed on well characterized test objects and biological samples. The images obtained were compared with images obtained by the conventional absorption contrast method. The diffraction enhanced images of test objects, insect and breast tissues with cancer showed higher resolution as compared with the conventional images mainly from the boundaries of the sample. The tissue with invasive lobular carcinoma had details increased when compared with a conventional image, but it was not possible to clearly visualize the interfaces of the tumour in this case. The diffraction enhanced images had higher quality because this system uses an analyzer crystal placed after the sample. This crystal serves as a narrow angular slit which resulted in images with gain in contrast as compared to the conventional images methods. The DEI algorithm to obtain two new images so called "Apparent Absorption" and "Refraction" images were used to the breast tissue and test objects images taken at symmetrical half intensity sides of the rocking curve. Furthermore, this algorithm was also used to images taken at symmetrical positions of the analyzer further away from the top resulting in images with higher resolution and signal to noise ratio.
Mestrado
Física da Matéria Condensada
Mestre em Física
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Santos, Amanda Cristina dos. "Avaliação da qualidade da imagem e dose na paciente em mamografia analógica e digital." Universidade Tecnológica Federal do Paraná, 2011. http://repositorio.utfpr.edu.br/jspui/handle/1/301.
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Este trabalho foi motivado por um estudo maio, proposto pela Agência Internacional de Energia Atômica (IAEA). O objetivo do trabalho foi estimar o kerma incidente (Ki) e a dose glandular média (Dg) em pacientes submetidas a mamografias nas projeções crânio-caudal (CC) e médio-lateral-oblíqua (MLO), nos sistemas de aquisição de imagens analógico e digital CR. A estimativa foi realizada através de cálculos matemáticos, tendo como base estudos computacionais utilizando simulações de Monte Carlo. Este estudo fez parte de um estudo maior em mamografia, coordenado pela IAEA, cujos dados fizeram parte da representação dos dados brasileiros no estudo da América Latina. Foram escolhidas mamografias cuja mama exposta tinha aproximadamente 50% de glandularidade e 50% de adiposidade. Dados da técnica radiográfica utilizada nos exames, assim como a espessura da mama comprimida, foram registrados em planilhas especificas e o cálculo foi realizado com base em testes de rendimento do tubo de raios X dos mamógrafos. Além disso, as mamografias acompanhadas foram analisadas quanto a critérios de qualidade da imagem. Foram acompanhadas 100 exposições, sendo 50 analógicas e d 50 digitais. Os resultados mostraram que as imagens foram predominantemente aceitas quanto aos critérios de qualidade da imagem estabelecidos pala IAEA, com melhores resultados do sistema digital. Os valores de Ki e Dg encontrados para o objeto simulador estavam de acordo com o recomendado, mas os calculados para as pacientes estavam mais altos, principalmente o Ki. O sistema digital obteve doses mais baixas e melhor qualidade de imagem. Os resultados sugerem que os exames devem ser realizados com o devido cuidado, de maneira a oferecer qualidade de imagem para o diagnóstico em doses tão baixas quanto razoavelmente exeqüíveis. O treinamento contínuo dos profissionais da mamografia deve ser realizado de maneira e oferecer exames adequados ao diagnóstico, protegendo os pacientes e mantendo a qualidade do serviço a todos.This work has been motivated by a larger study, proposed by the International Atomic Energy Agency (IAEA). The aim of this work was to estimate the incident kerma (Ki) and mean glandular dose (Dg) in patients who underwent mammograms in craniocaudal projections (CC) and mediolateral-ablique (MLO), at analog and digital systems. The estimation was performed using mathematical calculations based on computational studies using Monte Carlo simulations. This study was part of a larger study in mammography, coordinated by the IAEA, whose data were included in the representation of Brazilian data in the study of Latin America. Mammograms with 50% of glandular tissue and 50% of fat were selected. Data from the radiographic technique used in the examinations, as well as the compressed breast thickness were recorded in spreadsheets and specific calculation was made based on output tests of the X-ray tube for mammography. In addition, the mammograms were analysed with the criteria of image quality. The amount of examinations was 100 mammograms, 50 analog and 50 digital. The results showed that the images were largely accepted as the criteria for image quality established by the IAEA, with better results from digital system. The values of Ki and Dg for the phantom were according to the recommended, but those calculate for the patients were higher, especially the Ki. Digital system produced lower dosis and better results on image quality. The results suggests that the examinations must be conducted with due care in order to offer image quality in dosis as low as reasonably achievable. The permanent training of mammographers should be conducted in a manner to provide exams with quality, protecting the patient and maintaining the quality of service to all patients treated.
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Thacker, Samta C. "Development of a Monte Carlo simulation method for use in investigating CT (Computed Tomography) mammography." Link to electronic thesis, 2004. http://www.wpi.edu/Pubs/ETD/Available/etd-0430104-153425.
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Suryanarayanan, Sankararaman. "Design, Development, and Characterization of a Prototype Digital Mammography System." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/14515.
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Breast cancer is a major health concern in the United States. Mammography is the gold standard for screening breast cancer and screen-film technology is still widely used in the screening for breast cancer. However, screen-film systems have limited dynamic range and contrasts compared to digital systems, and do not offer integrated image processing capabilities. Recently, digital mammography has seen an upsurge in clinical adoption but current digital mammography systems are limited in terms of their spatial resolution. Therefore, high-resolution digital mammography systems with superior signal-to-noise ratio and contrast characteristics need to be explored.
A monolithic, single module high-resolution (39 um) digital x-ray platform (Fairchild Imaging Inc., Milpitas, CA) was developed and characterized for digital mammography. The architecture was extended to a large area (16 x 24-cm) multi-module solid-state imager with variable resolution (39 and 78-um). In addition, a four module (16 x 16-cm) imaging architecture with 78-um pixel was explored for high-resolution contrast enhanced digital mammography for the detection of malignancy-associated angiogenesis. Simulations based on the cascaded linear systems framework were performed in order to characterize the physical properties of the imaging platforms such as the modulation transfer function (MTF), noise power spectra (NPS), and detective quantum efficiency (DQE). Experimental measurements of imager performance was also conducted and compared to model predicted results. Further, perceptual analysis of the prototype imaging platform for digital mammography was performed.
Various imaging platforms were successfully developed and investigated to identify essential parameters for high-resolution digital x-ray breast imaging. The single module prototype exhibited physical characteristics that are favorable for digital mammography. Good agreement between model and experimental results were observed demonstrating the utility of such models for further system improvement. The large area 16 x 24-cm prototype demonstrated superior contrast-detail characteristics compared to a clinical FFDM system (100 um pixel) at both 39 and 78-um pixel sizes. Both experimental and theoretical results pointed towards the feasibility of contrast enhanced mammography at mean x-ray glandular dose levels substantially lower than mammography under the conditions investigated. Qualitative analysis of contrast enhanced digital mammography indicated favorable image quality.
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Messias, Pricila Cordeiro. "Controle de qualidade, medição de dose glandular média e protocolo de rotina para tomossíntese digital mamária." Universidade Tecnológica Federal do Paraná, 2016. http://repositorio.utfpr.edu.br/jspui/handle/1/1881.
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No Brasil, o câncer de mama é o mais frequente e a principal causa de morte entre as mulheres, para o ano de 2016 foram estimados 57.960 mil novos casos. A Tomossíntese Digital Mamária (TDM) reduz os efeitos da sobreposição do tecido da mama, oferecendo uma melhor caracterização dos achados mamográficos e diminuindo a necessidade de incidências adicionais. A recente introdução da TDM na prática clínica requer manutenção dos requisitos de dose e qualidade da imagem, além de rotinas de Controle de Qualidade (CQ) e monitoração da Dose Glandular Média (DGM), e também uma equipe técnica qualificada para executar o procedimento. A prática de monitoração da qualidade da imagem e da dose de radiação é uma solução para assegurar continuamente a alta qualidade de exames de radiodiagnóstico. São poucos os estudos relacionados ao CQ em TDM no Brasil, e ainda não foram estabelecidos protocolos nacionais e internacionais específicos; sendo assim, os testes de CQ utilizados são baseados naqueles utilizados pela National Health Service Breast Screening Programme (NHSBSP), European Reference Organisation for Quality Assured Breast Screening and Diagnostic Service (EUREF), American Association of Physicists in Medicine (AAPM), Internacional Atomic Energy Agency (IAEA). Este estudo propõe e apresenta os resultados dos testes de CQ e DGM para mamografia e TDM, e um Protocolo de Rotina para exames de TDM. Os testes de CQ para TDM foram realizados conforme as recomendações do fabricante, da Portaria 2898/13 e de protocolos internacionais. O Protocolo de Rotina foi elaborado visando sanar as dúvidas mais frequentes da equipe técnica, assim como otimizar a qualidade do exame em sala. Para atestar a qualidade da imagem diagnóstica para todas as espessuras, foi realizado o teste de Qualidade de Imagem do simulador padrão do American College of Radiology (ACR). Na avaliação da DGM todos os valores obtidos para mamografia e TDM se mantiveram em conformidade com os limites de referência utilizados, exceto para a espessura de 20 mm em TDM. Para todos os outros testes de CQ, os resultados se mantiveram em conformidade com os limites de referência. Os resultados adquiridos nas avaliações reforçam a importância do controle de qualidade aplicado de forma adequada no processo de obtenção das imagens, assegurando baixa dose e boa qualidade da imagem, cumprindo o princípio ALARA.In Brazil, breast cancer is the most common and the leading cause of death among women; in 2015, 57,120,000 new cases. Digital Breast Tomosynthesis (DBT) reduces the effects of overlapping breast tissue, offering a better characterization of mammographic findings and decreasing the need of additional views. The recent introduction of DBT in clinical practice requires, in order to maintain the dose requirements and image quality, aside from routine Quality Control (QC) procedures and monitoring the Mean Glandular Dose (MGD) also a qualified technical team to perform the procedure. The practice of monitoring the image quality and the radiation dose is a solution to continuously ensure high quality diagnostic radiology exams. Few studies related to CQ TDM in Brazil, and national and international specific protocols have not been established, Thus, QC tests used are based on those used by the National Health Service Breast Screening Programme (NHSBSP), European Reference Organization for Quality Assured Breast Screening and Diagnostic Service (EUREF), American Association of Physicists in Medicine (AAPM), International Atomic Energy Agency (IAEA). This study proposes and presents the results of the QC tests and DGM for mammography and TDM, and routine protocol for TDM tests. The QC tests for TDM were performed according to the manufacturer's recommendations, of Portaria 2898/13 and international protocols. The Routine Protocol was elaborated aiming to resolve the most frequent doubts of the technical team, as well as optimize the room examination. In order to certify the quality of the diagnostic image for all thicknesses, a imagine quality test from the standard simulator of American College of Radiology (ACR) was performed. In the DGM evaluation, all values mammography and TDM remained in accordance with the reference range used except for 20 mm TDM. For all other QC tests, the results remained in accordance with the reference limits. The results obtained in the assessments emphasize the importance of quality control applied properly in obtaining the imaging process, ensuring low dose and good image quality, fulfilling the ALARA principle.
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Jakubiak, Rosangela Requi. "Qualidade da imagem, limiar de contraste e dose glandular média em mamografia digital CR." Universidade Tecnológica Federal do Paraná, 2013. http://repositorio.utfpr.edu.br/jspui/handle/1/572.
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Em muitos países, os sistemas de radiologia computadorizada (CR) representam a maioria dos equipamentos usados em mamografia digital. Este estudo apresenta um método para a otimização da qualidade da imagem e da dose em mamografia digital CR para pacientes com mamas de espessuras entre 45 e 75. As espessuras das mamas foram simuladas com placas de polimetilmetacrilato (PMMA). Técnicas de exposição otimizadas (tensão (kV), produto corrente-tempo (mAs) e combinação alvo/filtro) foram definidas como aquelas que fornecem uma razão contraste-ruído (CNR) ideal, denominada CNR alvo, que permite atingir o limiar de contraste das imagens do detalhe de diâmetro de 0,10 mm no simulador CDMAM (versão 3.4 Artinis Medical Systems, Netherlands) com um padrão de Dose Glandular Média (DGM) aceitável. Os resultados foram utilizados para os ajustes do Controle Automático de Exposição (CAE) pela equipe de manutenção. Um estudo retrospectivo de dois grupos de pacientes (Grupo 1-antes do ajuste do CAE e Grupo 2- após o ajuste do CAE) foi realizado. Os parâmetros de exposição foram reproduzidos nos simuladores para a determinação da CNR, da DGM e do limiar de contraste. As imagens clínicas destes pacientes foram analisadas por três radiologistas especialistas em mamografia que responderam questões sobre as estruturas anatômicas, ruído e contraste em áreas de valores de pixels altos ou baixos, sobre nitidez e contraste da imagem. Os resultados mostram que o método proposto foi efetivo para todas as espessuras de mama avaliadas. O ajuste do CAE proporcionou a concentração de valores da CNR no Grupo 2 mais próximas ao CNR alvo e que, mesmo como aumento do nível de ruído nas imagens clínicas, as análises do CDMAM mostraram que não houve prejuízo na identificação do objeto de 0,10 mm de diâmetro. Finalmente, este estudo conclui que o uso dos CAE das unidades de raios X baseados em fornecer uma dose constante ao detector pode ocasionar algumas dificuldades para alguns sistemas CR operarem nas condições ótimas.In many countries, computed radiography (CR) systems represent the majority of equipments used in digital mammography. This study presents a method for optimizing image quality and dose in CR mammography of patients with breast thicknesses between 45 to 75mm. The breast thicknesses were simulated with polymethylmetacrylate (PMMA). Optimazed exposure parameters ((voltage (kV), mA and time product (mAs) and target/filter combination)) was defined as giving an ideal contrast to noise ratio (CNR), defined as target CNR, to reach the threshold contrast of CDMAM (version 3.4) phantom (Artinis Medical Systems, Netherlands) images for acceptable mean glandular dose (MGD). These results were used for adjustments in the automatic exposure control (AEC) by the maintenance team. A retrospective study of two groups of patients (Group 1-before AEC adjustment and Group 2- after AEC adjustment) were done. The exposure parameters were reproduced in the phantoms to determine of CNR, MGD and threshold contrast. The clinical images of these patients were analyzed by three experienced radiologists who answered questions about anatomical structures, noise and contrast in low and high pixel value areas and image sharpness and contrast. The results showed that the proposed method was effective for all breast thickness evaluated. The AEC adjustment showed a concentration of CNR in Group 2 nearer of target CNR, and that the increasing of noise in clinical images, the CDMAM analysis showed that this level of noise did not disturb the detail of 0,1 mm diameter. Finally, this study also concluded that the use AEC of X rays unit based on constant dose to the detector may bring some difficulties to CR systems operate in optimal conditions.
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Oliveira, Evelyn Rosa de. "Avaliação do padrão de desempenho das equipes técnicas de mamografia frente ao uso de tecnologias digitais." Universidade Tecnológica Federal do Paraná, 2017. http://repositorio.utfpr.edu.br/jspui/handle/1/2626.
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Este estudo apresenta uma análise de rejeição, realizada na clínica Diagnóstico Avançado Por Imagem – DAPI, com dados de 647 mamografias rejeitadas realizadas de março a novembro de 2015, antes e após treinamentos realizados com a equipe técnica de mamografia, para análise do desempenho. As informações foram coletadas na base de dados do software de análise de rejeição dos mamógrafos, e incluem: incidência; quantidade de repetições; motivo da repetição; identificação da profissional; compressão do exame rejeitado e do exame aceito. Observou-se que após o treinamento os índices de rejeição por posicionamento (a maior causa das rejeições) foram reduzidos em 2%. Identificou-se que as profissionais desenvolveram critérios mais rigorosos, o que também contribuiu para aumento das repetições após o treinamento. A incidência mais rejeitada foi a Crânio Caudal Direita – CCD, tanto antes (32%) quanto após o treinamento (36%). A análise do desempenho da equipe técnica em relação aos critérios de qualidade em mamografia digital pôde ser realizada, uma vez que houve a análise individual das profissionais para contribuição da qualificação da equipe e aumento da qualidade dos exames. A profissional “A”, que possuía o maior índice de rejeição por posicionamento, após o treinamento houve uma redução de 17% das repetições devido a posicionamento inadequado. Foram identificadas imagens com qualidade aceitável que foram rejeitadas desnecessariamente: 8% antes e 3,6% após o treinamento. Antes do treinamento, a equipe técnica realizava as mamografias com valores de compressão entre 80 a 89 N, e após o treinamento a maioria dos exames foi realizada com 90 N ou mais. Esse aumento resulta em exames com melhor qualidade e menor dose para a paciente.This study presents a rejection analysis performed at the clinic Diagnóstico Avançado Por Imagem - DAPI, with data from 647 rejected mammograms performed three months before and three months after a training session of the mammography team, to analyze the performance of them after the training. The information was collected in the database of mammography rejection analysis software,these data include: Incidence; Number of repetitions; Reason for the repetition; Identification of the professional; Rejection examination and accepted examination. It was observed that, after the training, the rejection indexes by positioning (the greatest cause of the rejections) were reduced. It was observed that the group developed rigorous criteria, which also contributed to increase the repetitions after the training. The most rejected incidence was Cranio Caudal Right - CCD, both before (32%) and after training (36%).The analysis of the performance of the technical team, in relation to the quality criteria in digital mammography, could be performed by the individual analysis of the professionals to contribute to the qualification of the team and to increase the quality of the exams. The "A" professional, who had the highest index of rejection by positioning, after the training there was a reduction of 17% of the repetitions due to improper positioning. Acceptable quality images have been identified that are rejected unnecessarily 8% before and 3,6% after training. Before the training, the technical team performed the mammograms with values of compression between 80 and 89 N, and after training most of the exams were performed with 90 N or more. This increase which results in better quality tests and lower dose for the patient.
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Carr, Douglas. "Developing the radiographer film reading role : an illustrative case in breast screening." Thesis, University of Derby, 2006. http://hdl.handle.net/10545/304841.
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McGarry, Gregory John. "Model-based mammographic image analysis." Thesis, Queensland University of Technology, 2002.
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Nilsson, Maria, and Olga Bittenbinder. "Faktorer som kan påverka kvinnors smärtupplevelse vid screeningmammografi ur röntgensjuksköterskans perspektiv : Litteraturöversikt." Thesis, Luleå tekniska universitet, Institutionen för hälsovetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-82049.
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Inledning: Mammografi är en vanlig bröstundersökning där kvinnor mellan 40–74 år erbjuds screening av bröst med regelbundna intervaller. Kvinnor som upplever mammografi-undersökningen som smärtsam och obehaglig återkommer ibland inte till sina kontroll-undersökningar. Uteblivna kontroller kan leda till högre mortalitet i bröstcancer. Syfte: Studiens syfte var att kartlägga kunskap om faktorer som påverkar kvinnors smärtupplevelse i samband med screeningmammografi. Metod: Studien är en allmän litteraturöversikt som genomförts via databaserna, Cinahl och PubMed. I huvudsak kvantitativa artiklar har analyserats och kvalitetsgranskats. Resultatet från de granskade artiklarna har ordnats systematisk som underlag för analysen. Resultat: Studiens resultat var att den största delen av smärta och obehag uppkom under bröstkompression. Röntgensjuksköterskans kunskap om möjliga åtgärder som bemötande, information före och efter undersökningen samt individuell anpassning av undersökningen har betydelse. Detta kan göra skillnad för kvinnors upplevelse och bidra till en positiv upplevelse vid mammografiundersökningen. Slutsats: Studiens resultat visar att orsaker till kvinnors smärta vid screeningmammografi är komplexa. Tekniken för mammografi har utvecklats över tid, däremot upplever kvinnorna fortfarande obehag och smärta. Samband kan finnas med tekniken, röntgensjuksköterskans bemötande och brist på information till kvinnorna men forskningen ger inget säkert stöd för slutsatser annat än att bemötandet och patientkommunikation spelar stor roll. Det behövs mer forskning kring olika metoder för de åtgärder en röntgensjuksköterska kan använda för att lindra kvinnors smärtupplevelse vid screeningmammografi.Introduction: Mammography is a common breast examination where women between the ages of 40–74 are offered breast screening at regular intervals. Women who experience the mammography examination as painful and uncomfortable sometimes do not return to their check-ups. Lack of control can lead to higher mortality in breast cancer. Aim: The purpose of the study was to chart knowledge about factors affecting women´s experience of pain during screening mammography. Method: The study is a general literature review conducted via the databases, Cinahl and PubMed. Mainly quantitative articles have been analyzed and quality reviewed. The results from the reviewed articles have been arranged systematically as a basis for the analysis. Results: The results of the study were that most of the pain and discomfort arose during breast compression. Radiographer's knowledge of enabling measures such as treatment, information before and after the examination and individual adaptation of the examination is important. This can make a difference to women's experience and contribute to a positive atmosphere at the mammography examination. Conclusion: The results of the study show that the causes of women's pain during screening mammography are complex. The technique of mammography has evolved over time; however, women still experience discomfort and pain. There may be a connection with the technology, the radiographer's treatment and lack of information for the women, but the research does not provide definite support for conclusions other than that the treatment and patient communication play a major role. More research is needed on different methods for the measures a radiographer's can use to relieve women's pain experience during the screeningmammography.
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Milan, Ranisavljević. "Дијагностичка вредност мобилне дигиталне радиографије у процени позитивности ресекционих хируршких маргина код карцинома дојке." Phd thesis, Univerzitet u Novom Sadu, Medicinski fakultet u Novom Sadu, 2020. https://www.cris.uns.ac.rs/record.jsf?recordId=114074&source=NDLTD&language=en.
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Karcinom dojke predstavlja najčešću malignu neoplazmu među ženskom populacijom, a poštedna terapija dojke, preferirani je model lečenja bolesnica u ranom stadijumu bolesti. Smatra se da je optimalna hirurška resekciona margina 2 mm. Opisano je mnogo metoda koje služe za intraoperativnu proveru suficijentnosti resekcione hirurške margine i sve one imaju svoje prednosti i mane. Ciljevi ove studije bili su da se utvrdi, da li postoji statistički značajna razlika u određivanju širine negativne resekcione hirurške margine izražene u milimetrima pri operacijama karcinoma dojke upotrebom palpatorne metode i intraoperativne mobilne radiografije, poređenjem nalaza merenja hiruga sa većim i manjim iskustvom u hirurgiji karcinoma dojke kao i nalaza radiologa u odnosu na patohistološku ex tempore analizu. Istraživanje je sprovedeno kao retrospektivno–prospektivna studija na Klinici za operativnu onkologiju, Instituta za onkologiju Vojvodine i obuhvatilo je 150 bolesnica kod kojih je preoperativno dijagnostikovan karcinom dojke. Kriterijum za uključenje u studiju bilo je izvođenje poštedne operacije dojke sa ili bez disekcije ipsilaterale aksile, dok su iz studije isključene bolesnice kod kojih nije bilo moguće izvesti poštednu operaciju dojke, one sa radiološki potvrđenom diseminovanom bolešću, kao i bolesnice koje su ranije operisane zbog karcinoma iste dojke. Kod svih 150 ekstirpiranih karcinoma dojke urađena je procena širine resekcione hirurške margine intraoperativno palpatornom metodom, zatim na aparatu za mobilnu digitalnu radiografiju, te radiogram analiziran od strane iskusnog i manje iskusnog hiruga u hirurgiji karcinoma dojke, kao i radiologa te upoređen sa nalazom ex tempore patohistološke analize. Definitivna širina resekcione hirurške margine potvrđena je na parafinskim patohistološkim preparatima. Srednja vrednost praćenja bolesnica, postoperativno, iznosila je 100,97 nedelja. Najveći broj bolesnica pripadao je starijoj životnoj dobi (56,67%). Preoperativna lokalizacija klinički nepalpabilnih tumora u dojci urađena je kod 52 (34,67%) bolesnice. Najčešće se tumor prezentovao kao solitarni fokus sa okolnim ognjištima in situ karcinoma (72, 48%), dok je najčešći histološki subtip bio duktalni invazivni karcinom dojke (112 (74,67%)). Najveći broj operacija dojke okarakterisan je kao kvadrantektomija (85 (56,67)), dok je najučestalija operacija aksile bilo određivanje limfnog čvora stražara (119 (79,33%). Analizom rada aparata za mobilnu digitalnu radiografiju došli smo do saznanja da nema statistički značajne razlike u oceni kvaliteta radiograma i širine resekcione hirurške margine merene na aparatu za mobilnu digitalnu radiografiju između iskusnog hirurga i radiologa. Statistički značajna razlika nije uočena ni pri merenju širine resekcione hirurške margine izražene u milimetrima na aparatu za mobilnu digitalnu radiografiju od strane iskusnog hirurga i radiologa u odnosu na ex tempore patohistološku analizu, dok je ista uočena nakon definitivne patohistološke analize. Šansa doresekcije tkiva dojke nakon merenja na aparatu za mobilnu digitalnu radiografiju je 1,4 puta veća nego nakon patohistološke ex tempore analize. Lokalni recidiv javio se kod jedne pacijentkinje tokom perioda praćenja. Ne postoji statistički značajna razlika u određivanju širine resekcione hirurške margine izražene u milimetrima upotrebom aparata za mobilnu digitalnu radiografiju od strane iskusnog hirurga i radiologa u odnosu na patohistološku ex tempore analizu, dok ista postoji nakon analize radiograma od strane manje iskusnog hirurga. Palpatorna metoda se ne može smatrati sigurnom metodom u određivanju širine hirurške resekcione margine. Ne postoji statistički značajna razlika u broju doresekcije tkiva dojke između hirurga sa različitim hirurškim iskustvom.Breast cancer is the most common malignant neoplasm in the female population, and conservative breast therapy is the preferred treatment model for patients in early stages of the disease. The optimal surgical resection margin, from healthy breast tissue around the primary tumor is 2 mm. Many methods have been described that serve to check the resection margin during breast conservative surgery and all of them have their advantages and disadvantages. The aim of this study was to determine whether there was a statistically significant difference in the determination of the width of the negative resection margin expressed in millimeters in breast cancer surgery using palpatory method and intraoperative mobile specimen radiography, comparing the findings of measuring of surgeons with greater and lesser experience in breast cancer surgery as well as the findings of the radiologist in relation to histopathological ex tempore and definitive histopathological analysis. The study was conducted as a retrospective - prospective study at the Clinic for Operative Oncology, Oncology Institute of Vojvodina and included 150 patients who were preoperatively diagnosed with breast cancer. The criterion for inclusion in the study was the opportunity to perform breast conservative surgery with or without complete axillary lymph node dissection. Patients that were treated with breast amputation, those with radiological confirmed disseminated disease, as well as patients previously operated from cancer were excluded from the study. For all 150 extirpated breast cancers, an estimate of the width of the resection surgical margin was performed intraoperatively with a palpatory method, followed by measuring on device for mobile specimen digital radiography, and a radiogram was analyzed by an experienced and less experienced surgeon in breast cancer surgery, as well as by a radiologist and compared with an ex tempore histopathological analysis. The definitive width of the resection surgical margin was confirmed on histopathological preparations. The mean follow-up, postoperatively, was 100.97 weeks. The majority of patients belonged to the elderly age (56.67%). Preoperative localization of clinically impalpable breast tumors was performed in 52 (34.67%) patients. Most often the tumor was presented as a solitary focus with surrounding foci of in situ cancer (72, 48%), while the most common histological subtype was invasive ductal breast cancer (112 (74.67%)). The majority of breast operations were characterized like quadrantectomy (85 (56.67)), while the most frequent axillary surgery was the determination of the sentinel lymph node (119 (79.33%). No significant difference was observed in the evaluation of radiography quality and the width of the resection surgical margin measured on the mobile digital radiography device between the experienced surgeon and the radiologist. No statistically significant difference was observed in the measurement of the width of the resection surgical margin expressed in millimeters on the mobile digital radiography device by the experienced surgeon and radiologist versus ex tempore histopathological analysis, while the statistical difference was observed after definite histopathological analysis. The chance of breast tissue reexcision after measurement on a mobile digital radiography device is 1.4 times higher than after histopathological ex tempore analysis. Local relapse occurred in one patient during the follow-up period. There is no statistically significant difference in the determination of the width of the resection surgical margin expressed in millimeters using a mobile digital radiography device by an experienced surgeon in breast cancer surgery and radiologist with respect to histopathological ex tempore analysis. However, the statistical difference exists after radiogram analysis by a less experienced surgeon. The palpatory method cannot be considered as a safe method in determining the width of a surgical resection margin. There is no statistically significant difference in the number of breast tissue additional resections between surgeons with different surgical experience.
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Nataša, Prvulović Bunović. "Дигитална мамографија и томосинтеза у детекцији и радиолошкој БИ РАДС категоризацији туморских лезија дојке." Phd thesis, Univerzitet u Novom Sadu, Medicinski fakultet u Novom Sadu, 2015. http://www.cris.uns.ac.rs/record.jsf?recordId=92756&source=NDLTD&language=en.
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Циљ ове студије је да се упореди дијагностичкa значајност 2Д и 2Д+3Д мамографије у детектовању тумора дојке. Испитивали смо 864 дојки у 740 пацијенткиња. Студија је спроведена у току рутинског рада у Центру за имиџинг дијагностику Институту за онкологију Војводине. 2Д + 3Д мамографија су начињене појединачно или у истом акту снимања као комбо опција на Selenia Dimensions апарату произвођача фирме Холоџик. Радиолошки извешатаји су класификовани у категорије 1-5 према АЦР БИ РAДС-у. Патохистолошка верификација је вршена у свих суспектних промена или у току њиховог праћења . Све пацијенткиње са уредним налазом или мамографски уочених бенигних промена су радиолошки праћене најкраће током 2 године. Уочено је 103 малигне лезије у дојкама класификованих као БИ РАДС 4, 5 на дигиталној мамографији и у 22 дојке чије су промене класификоване као БИ РАДС 1-3, током праћења или прегледа дојки помоћу других модалитета. На 2Д + 3Д мамографији малигните је потврђен у 125 дојке од којих је 118 класификовано као БИ РАДС 4,5 и у 7 дојки чује су промене категорисане у БИРАДС 1-3. Постоји статистички значајна разлика у дистрибуцији малигних налаза у односу на подгрупе Студија је показала 20% лажно негативних налаза на 2Д, а 5,6% на 2Д + 3Д модалитету прегледа дојки. Осетљивост у откривању рака у овој студији износи 82,4% на 2Д и 94,4% на 2Д+3Д методи прегледа, док је специфичност 90,5% и 92,0%, респективно. ППВ је већа за 2Д + 3Д технику прегледа , износи 66,7%, као и негативна предиктивна вредност која износи 99,0%. У 172 случаја (19, 9%) налази 2Д мамографије се не уочавају на 3Д техници прегледа и сматрају се последицом структурне или анатомске „буке“. Већина не -сталних налаза (85%) је класификовано као фокална асиметрија. У овој студији 500 дојки је класификовано према АЦР структури у масне (АЦР 1) или дифузне фибро-гландуларне (АЦР 2), а преосталих 264 је било хетеродензно (АЦР 3) и значајно дензно (АЦР 4). Статистички значајна разлика није показана приликом дистрибуције малигних налаза у поређењу са подгрупама дојки начињеним према њиховој густини - складу са правилима АЦР-а. Укупна тачност теста износи 89,4% за 2Д и 92,4% за 2Д + 3Д мамографију. Предиктивне вредности добијене за 2Д + 3Д мамографију су боље од оних које се односе само на 2Д мамографију, што је резултат њене веће осетљивости и шире могућности карактеризације промена. Варијабилност у интерпретацији налаза међу два радиолога је је ниска, показано је слагање у интершпретавцији евалуираних мамограма у 94.1% случајева.Cilj ove studije je da se uporedi dijagnostička značajnost 2D i 2D+3D mamografije u detektovanju tumora dojke. Ispitivali smo 864 dojki u 740 pacijentkinja. Studija je sprovedena u toku rutinskog rada u Centru za imidžing dijagnostiku Institutu za onkologiju Vojvodine. 2D + 3D mamografija su načinjene pojedinačno ili u istom aktu snimanja kao kombo opcija na Selenia Dimensions aparatu proizvođača firme Holodžik. Radiološki izvešataji su klasifikovani u kategorije 1-5 prema ACR BI RADS-u. Patohistološka verifikacija je vršena u svih suspektnih promena ili u toku njihovog praćenja . Sve pacijentkinje sa urednim nalazom ili mamografski uočenih benignih promena su radiološki praćene najkraće tokom 2 godine. Uočeno je 103 maligne lezije u dojkama klasifikovanih kao BI RADS 4, 5 na digitalnoj mamografiji i u 22 dojke čije su promene klasifikovane kao BI RADS 1-3, tokom praćenja ili pregleda dojki pomoću drugih modaliteta. Na 2D + 3D mamografiji malignite je potvrđen u 125 dojke od kojih je 118 klasifikovano kao BI RADS 4,5 i u 7 dojki čuje su promene kategorisane u BIRADS 1-3. Postoji statistički značajna razlika u distribuciji malignih nalaza u odnosu na podgrupe Studija je pokazala 20% lažno negativnih nalaza na 2D, a 5,6% na 2D + 3D modalitetu pregleda dojki. Osetljivost u otkrivanju raka u ovoj studiji iznosi 82,4% na 2D i 94,4% na 2D+3D metodi pregleda, dok je specifičnost 90,5% i 92,0%, respektivno. PPV je veća za 2D + 3D tehniku pregleda , iznosi 66,7%, kao i negativna prediktivna vrednost koja iznosi 99,0%. U 172 slučaja (19, 9%) nalazi 2D mamografije se ne uočavaju na 3D tehnici pregleda i smatraju se posledicom strukturne ili anatomske „buke“. Većina ne -stalnih nalaza (85%) je klasifikovano kao fokalna asimetrija. U ovoj studiji 500 dojki je klasifikovano prema ACR strukturi u masne (ACR 1) ili difuzne fibro-glandularne (ACR 2), a preostalih 264 je bilo heterodenzno (ACR 3) i značajno denzno (ACR 4). Statistički značajna razlika nije pokazana prilikom distribucije malignih nalaza u poređenju sa podgrupama dojki načinjenim prema njihovoj gustini - skladu sa pravilima ACR-a. Ukupna tačnost testa iznosi 89,4% za 2D i 92,4% za 2D + 3D mamografiju. Prediktivne vrednosti dobijene za 2D + 3D mamografiju su bolje od onih koje se odnose samo na 2D mamografiju, što je rezultat njene veće osetljivosti i šire mogućnosti karakterizacije promena. Varijabilnost u interpretaciji nalaza među dva radiologa je je niska, pokazano je slaganje u interšpretavciji evaluiranih mamograma u 94.1% slučajeva.
The aim of this study was to compare diagnostic importance of 2D and 2D+3D diagnostic mammography in breast tumor detection. We evaluated 864 breasts in 740 patients. Study was performed in Diagnostic Imaging Center at Oncology Institute of Vojvodina. 2D+3D mammography were performed during single procedure or via combo option at Selenia Dimensions unit, Hologic, BE. Radiological findings were classified in categories 1-5 according to ACR BIRADS. Pathohistologic verification was obtained in all suspicious findings or after follow up studies. All other patients with mammographic normal findings or benign findings were fallowed up during 2 years period or longer. We detected malignant lesions in 103 breasts classified as BIRADS 4,5 at digital mammography, and in 22 breasts classified as BIRADS 1-3 after followed up or diagnosed by other imaging modalities. At 2D+3D mammography malignancy was confirmed in 125 breasts, 118 classified as BIRADS 4,5 and in 7 breasts classified as BIRADS 1-3. There is statistically significant difference (p<0.001) in distribution of malignant findings compared to the subgroups classified according to 2D mammography. There was 20% false negative findings on 2D, and 5.6% on 2D+3D modality. Sensitivity in cancer detection in this study is 82.4% and 94.4% for 2D and 2D+3D mammography, while specificity is 90.5% and 92.0%, respectively. PPV is higher for 2D+3D technique (66.7%), as well as negative predictive value (99.0%). In 172 cases (19, 9%) 2D mammography findings did not persist on 3D mammography and were considered as structural or anatomical noise. The majority of the non-persistent findings (85%) were classified as asymmetric focal density. In this study 500 breast were classified according to ACR as fatty (ACR 1) or scattered fibroglandular densities (ACR 2), and the remaining 264 had heterogeneously (ACR 3) and extremely dense breasts (ACR 4). Statistically significant difference (p<0.001) was not shown in distribution of malignant findings compared to the subgroups of density structure according to ACR. Overall accuracy of the test was 89.4% and 92.4% for 2D and 2D+3D mammography, respectively. Predictive values obtained in 2D+ 3D mammography are better than those for 2D mammography alone, as a result of its higher sensitivity and better possibility of lesion characterization. Interobserver variability is low, there is an agreement between two radiologist between two radiologic interpretations in 94.1% cases.
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Herd, Olivia Jayne. "Analysis of radiosensitivity in South African cervical and breast cancer patients." Thesis, 2015. http://hdl.handle.net/10539/18487.
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Introduction: Ionising radiation can cause DNA double strand breaks (DSB), that result in chromosomal aberrations if un- or mis-repaired. Individuals with compromised DNA damage repair mechanisms display increased chromosomal radiosensitivity. The G0-micronucleus assay (MN assay) and the γ-H2AX assay are two assays used in radiobiology to study DNA DSB and repair.
Breast cancer is the leading cancer amongst South African women, with a lifetime risk of 1 in 34. Since most cancer patients in South Africa present with late-stage disease, chemotherapy and radiotherapy are commonly-used treatments. Several international studies have shown breast cancer patients to be more chromosomally radiosensitive than healthy controls. These studies have not been confirmed on a cancer population living in South Africa.
Cervical cancer is the second most common cancer in South Africa; however, it is the leading cancer amongst black women with a lifetime risk of 1/35 compared to 1/82 in white women. Studies show a genetic link to cervical cancer susceptibility and DNA damage repair genes. International studies on radiation-induced DNA damage in lymphocytes of cervical cancer patients remain inconclusive and have never been performed on a South African population. Cervical cancer is caused by infection with the Human Papilloma Virus (HPV). Human Immunodeficiency Virus (HIV), HPV and cervical cancer are epidemiologically linked. Due to the high rate of HIV in South Africa, a significant proportion of cervical cancer patients receiving radiotherapy treatment will be HIV-positive. Studies show an effect of HIV on chromosomal radiosensitivity, however this has not been confirmed on a cancer population. The MN assay on the biopsies and exfoliated cervical cells of cervical cancer
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Vujovic, Nenad. "Registration of time-sequences of random textures with application to mammogram follow-up /." Diss., 1997. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:9734881.
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Maskarinec, Gertraud. "The impact of mammography utilization on breast cancer incidence in Hawaii." Thesis, 1996. http://hdl.handle.net/10125/9393.
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Sampat, Mehul Pravin. "Evidence-based detection of spiculated lesions on mammography." Thesis, 2006. http://hdl.handle.net/2152/2914.
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Govender, Yoguvathie. "An evaluation of computerised tomography (CT) based treatment planning versus digitised image planning (standard planning technique) for carcinoma of the breast, using the four field breast technique." Thesis, 2007. http://hdl.handle.net/10321/123.
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Thesis (M.Tech.: Radiography)-Dept. of Radiography, Durban University of Technology, 2007
xxiv, 142 leaves, Annexures A-LThe aim of the study was to evaluate CT-based treatment planning versus digitised image planning (standard planning technique) for carcinoma of the breast, using the four-field breast technique, in terms of the depth of supraclavicular and axillary nodes, the variability of the breast tissue and the dose inhomogeneity at the matchline.
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Janse, van Rensburg Mariska. "Application of ultrasound characteristics in the accurate prediction of benign versus malignant solid breast nodules." Thesis, 2012. http://hdl.handle.net/10210/7855.
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M.Tech.To determine whether a combination of real-time B-Mode ultrasound, Doppler Color flow and Power Doppler flow mapping would be reliable in differentiating benign from malignant breast nodules in an attempt to avoid unnecessary biopsies, where after ultrasound guidelines would be formulated. A quantitative cross-sectional comparative descriptive design in a study population which consisted of 62 women over the age of 35 years who came to Klerksdorp Radiology services for mammography. Both breast ultrasound imaging and mammography was used as a routine procedure as part of the workup for the classification of breast nodules, before histologic specimens were obtained. All nodules were classified according to the ultrasonographic BI-RADS lexicon and compared with the pathologic results. Of the 63 patients, 63 breast nodules were detected and confirmed by biopsy. Thirty seven (59%) nodules were found to be malignant and 26 (41%) were benign according to biopsy results. Mammography had 87% sensitivity and ultrasound 60% sensitivity in detecting malignancy. It is recommended that B-mode, Color Doppler flow and Power Doppler flow mapping be used in combination with mammography for screening as a gold standard.
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Andrews, Caryn. "The measurement of modesty among Jewish American women /." 2004. http://wwwlib.umi.com/dissertations/fullcit/3131504.
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Cheok, Frida. "Participation in mammographic screenings in South Australia / Frida Cheok." Thesis, 1998. http://hdl.handle.net/2440/19292.
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Includes bibliographical references (18 leaves).2 v. : ill., maps ; 30 cm.
Examines the factors that predict attendence to mammography screening by comparing various groups of attenders and non-attenders.
Thesis (Ph.D.) -- University of Adelaide, Dept. of Public Health, 1999
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Coyne, Jennifer Tressa. "Mammography screening : the role of the fear appeals and message framing, and the application of the health belief model and the extended parallel process model." Thesis, 2011. http://hdl.handle.net/1885/149749.
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Breast cancer is a prominent and severe disease affecting Australian women and a decrease in breast cancer mortality rates has been attributed to mammography screening. Phase one of this study tests the application of the Health Belief Model (HBM) with mammography screening behaviour, and further tests the value of an extended HBM involving three additional variables. Phase two of this study tests the Framing Postulate of Prospect Theory and attempts to explain results by using the Extended Parallel Process Model (EPPM) and the HBM. Participants included 269 women aged 50 to 69 years and included women who do, and women who do not, obtain regular mammograms. Participation involved completing an initial survey before reading one of three framed messages randomly assigned, and completing a subsequent survey. Survey items were based on the HBM and the EPPM. Results showed that the basic 4-factor HBM was significantly associated with screening behaviour - despite only one core HBM factor, perceived barriers, having an association on its own. The extended 7-factor HBM was found to be significantly more associated with screening behaviour than the 4-factor HBM. Results of the present study provide support for the use of fear appeals but indicate the HBM does not adequately account for the perceived benefits of the appeals. Results further showed the EPPM accounted for pre-existing screening behaviour, but not for the effects of the fear appeal. Results suggest further clarification is required as to the effects and explanations of fear appeals and message framing in applied settings related to mammography screening.
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Clarke, Philip M. "Valuing the benefits of health care in monetary terms with particular reference to mammographic screening." Phd thesis, 1997. http://hdl.handle.net/1885/144282.
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Louw, Amanda. "Preferences and perceptions of female patients undergoing mammography in Gauteng, South Africa." Thesis, 2012. http://hdl.handle.net/10210/7138.
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M.Tech.Mammography is most important in the detection of breast cancer but due to its intimate nature and the perception that it is uncomfortable and painful, many women do not optimally support mammography as a diagnostic and screening tool for breast cancer. Many factors influence the mammogram experience of patients. This research explored the preferences and perceptions of patients regarding mammographer gender and personality traits as well as student involvement in mammogram procedures. To promote positive perceptions of mammography and to ensure the availability of adequately trained mammographers to meet the future demands of the profession, the preferences and perceptions of patients and training needs of students should be carefully balanced. The study was empirical in nature and data was collected using a valid and reliable self-formulated questionnaire. The approach was quantitative and a small qualitative component added dimension to the quantitative results. A nonprobability, convenience sampling method was employed and questionnaires were distributed in radiography training centres affiliated to the University of Johannesburg. Data analysis indicated that while many women accept males in the mammography setting, most prefer female mammographers and -students. In general, women accept student presence during mammogram procedures. Personality traits that enhance effective communication and promote patient emotions such as trust, being safe and being cared for are favoured by patients. This research adhered to stipulations of the South African Patients' Rights Charter and the call of the Breast Cancer Advocacy Coalition for South African research into breast health care. The findings serve as benchmarks for patient opinions regarding mammography staff and will be of use in various fields concerning mammography, such as human resources, training and education and quality assurance of care.
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Chawla, Amarpreet. "Correlation Imaging for Improved Cancer Detection." Diss., 2008. http://hdl.handle.net/10161/925.
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We present a new x-ray imaging technique, Correlation Imaging (CI), for improved breast and lung cancer detection. In CI, multiple low-dose radiographic images are acquired along a limited angular arc. Information from unreconstructed angular projections is directly combined to reduce the effect of overlying anatomy - the largest bottleneck in diagnosing cancer with projection imaging. In addition, CI avoids reconstruction artifacts that otherwise limit the performance of tomosynthesis. This work involved assessing the feasibility of the CI technique, its optimization, and its implementation for breast and chest imaging.
First a theoretical model was developed to determine the diagnostic information content of projection images using a mathematical observer. The model was benchmarked for a specific application in assessing the impact of reduced dose in mammography. Using this model, a multi-factorial task-based framework was developed to optimize the image acquisition of CI using existing low-dose clinical data. The framework was further validated using a CADe processor. Performance of CI was evaluated on mastectomy specimens at clinically relevant doses and further compared to tomosynthesis. Finally, leveraging on the expected improvement in breast imaging, a new hardware capable of CI acquisition for chest imaging was designed, prototyped, evaluated, and experimentally validated.
The theoretical model successfully predicted diagnostic performance on mammographic backgrounds, indicating a possible reduction in mammography dose by as much as 50% without adversely affecting lesion detection. Application of this model on low-dose clinical data showed that peak CI performance may be obtained with 15-17 projections. CAD results confirmed similar trends. Mastectomy specimen results at higher dose revealed that the performance of optimized breast CI may exceed that of mammography and tomosynthesis by 18% and 8%, respectively. Furthermore, for both CI and tomosynthesis, highest dose setting and maximum angular span with an angular separation of 2.75o was found to be optimum, indicating a threshold in the number of projections per angular span for optimum performance.
Finally, for the CI chest imaging system, the positional errors were found to be within 1% and motion blur to have minimal impact on the system MTF. The clinical images had excellent diagnostic quality for potentially improved lung cancer detection. The system was found to be robust and scalable to enable advanced applications for chest radiography, including novel tomosynthesis trajectories and stereoscopic imaging.
Dissertation