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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

Quantitative analysis of breast lumpectomies using histology and micro-CT data

Patel, Kunal 22 January 2016 (has links)
OBJECTIVE: Breast cancer represents a significant risk in women's health, affecting many women worldwide. Current treatment options in the U.S involve a multidisciplinary approach, most often beginning with surgery to remove cancerous tissue. Evaluation of margins for cancer on excised tissue is an important part of surgery, an important predictor of survival. As a result, there has been a great deal of research interest in intraoperative margin assessment, with a focus on fast and accurate results. Micro-computed Tomography (micro-CT) has emerged as a promising avenue to this end. We hypothesize that micro-CT scans will show a statistically significant difference in radiodensity between cancerous and non-cancerous tissue at intraoperative scan times. METHODS: 15 breast lumpectomy specimens were collected from patients undergoing surgery at Massachusetts General Hospital (MGH). Lumpectomies were scanned with a Nikon XTH225 Micro-CT scanner. Corresponding histology slides were scanned with a whole slide scanner, and matched with micro-CT scans. Representative areas of cancerous and non-cancerous tissues were segmented from micro-CT scans, and their respective radiodensity differences were tested for statistical significance. RESULTS: 9 of 15 lumpectomy cases were successfully matched with histology sections. Of the 9 cases matched, 8 showed a statistically significant difference in mean radiodensity. CONCLUSION: Due to potential confounds in the study, the results are difficult to deem conclusive. However, micro-CT remains a promising tool in margin assessment, and could be fit for clinical use with further study.
2

Densitometria óssea de gatas castradas e não castradas por tomografia computadorizada quantitativa

NOVACK, Nicholas 15 June 2015 (has links)
Submitted by Mario BC (mario@bc.ufrpe.br) on 2016-06-15T12:23:12Z No. of bitstreams: 1 Nicholas Novack.pdf: 1065518 bytes, checksum: 960193b642c76d9c5d7a0f4e56572f4f (MD5) / Made available in DSpace on 2016-06-15T12:23:12Z (GMT). No. of bitstreams: 1 Nicholas Novack.pdf: 1065518 bytes, checksum: 960193b642c76d9c5d7a0f4e56572f4f (MD5) Previous issue date: 2015-06-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Quantitative computerized tomography (QCT) is a highly sensitive technique, applied accurately diagnose loss of bone mass, bone mineral densitometry call with great advantages over plain radiography, but the lack of it limiting values for its clinical application. This study had the following objectives: establishing mean values of radiodensity the vertebral body of the second lumbar vertebra through the TCQ in cats, aspects involved in the pathophysiology of osteopenia induced by castration; study effects of depletion of estrogens radiodensity evaluate the characteristics of the female feline species of each experimental group, between the entire young cats and castrated adult cats spayed and not more than 6 years in a total of 22 animals. Comparing the degree of normality for young adult cats, and related. Statistically diseases was proven to be a reduction of bone mass in castrated cats over 6 years second lumbar vertebra L2. / A tomografia computadorizada quantitativa (TCQ) é uma técnica de alta sensibilidade, aplicada com precisão no diagnóstico de perda de massa óssea, chamada de densitometria mineral óssea, com grandes vantagens em relação à radiografia simples, porém a falta de valores de normalidade é limitante para a sua aplicação clínica. O presente trabalho teve os seguintes objetivos: estabelecer valores médios da radiodensidade do corpo vertebral da segunda vértebra lombar, através da TCQ, em gatas, aspectos envolvidos na fisiopatologia da osteopenia induzida pela castração; estudar efeitos da depleção dos estrógenos e avaliar as características da radiodensidade das fêmeas da espécie felina de cada grupo experimental, entre as gatas jovens inteiras e as gatas adultas castradas e não castradas acima de 6 anos, em um total de 22 animais. Comparando o grau de normalidade para as gatas adultas jovens e as patologias relacionadas. Estatisticamente comprovou-se uma redução de massa óssea em gatas castrada com mais de 6 anos na segunda vértebra lombar L2.

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