Global ETD Search

31	Separation of Water and Fat Signal in Magnetic Resonance Imaging : Advances in Methods Based on Chemical Shift Berglund, Johan January 2011 (has links) Magnetic resonance imaging (MRI) is one of the most important diagnostic tools of modern healthcare. The signal in medical MRI predominantly originates from water and fat molecules. Separation of the two components into water-only and fat-only images can improve diagnosis, and is the premier non-invasive method for measuring the amount and distribution of fatty tissue. Fat-water imaging (FWI) enables fast fat/water separation by model-based estimation from chemical shift encoded data, such as multi-echo acquisitions. Qualitative FWI is sufficient for visual separation of the components, while quantitative FWI also offers reliable estimates of the fat percentage in each pixel. The major problems of current FWI methods are long acquisition times, long reconstruction times, and reconstruction errors that degrade image quality. In this thesis, existing FWI methods were reviewed, and novel fully automatic methods were developed and evaluated, with a focus on fast 3D image reconstruction. All MRI data was acquired on standard clinical scanners. A triple-echo qualitative FWI method was developed for the specific application of 3D whole-body imaging. The method was compared with two reference methods, and demonstrated superior image quality when evaluated in 39 volunteers. The problem of qualitative FWI by dual-echo data with unconstrained echo times was solved, allowing faster and more flexible image acquisition than conventional FWI. Feasibility of the method was demonstrated in three volunteers and the noise performance was evaluated. Further, a quantitative multi-echo FWI method was developed. The signal separation was based on discrete whole-image optimization. Fast 3D image reconstruction with few reconstruction errors was demonstrated by abdominal imaging of ten volunteers. Lastly, a method was proposed for quantitative mapping of average fatty acid chain length and degree of saturation. The method was validated by imaging different oils, using gas-liquid chromatography (GLC) as the reference. The degree of saturation agreed well with GLC, and feasibility of the method was demonstrated in the thigh of a volunteer. The developed methods have applications in clinical settings, and are already being used in several research projects, including studies of obesity, dietary intervention, and the metabolic syndrome. Magnetic resonance imaging digital image reconstruction chemical shift imaging water and fat separation Dixon method fat suppression quantitative MRI whole-body MRI fatty acid composition fat unsaturation triglycerides adipose tissue liver fat T2* mapping Radiology Radiologi
32	The riotous presence in American literature and culture Biggio, Rebecca Skidmore. January 1900 (has links) Thesis (Ph. D.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains iv, 260 p. Vita. Includes abstract. Includes bibliographical references (p. 237-256).
33	Beyond "white supremacy:" white reactions to The Clansman and The Birth of a nation in New South North Carolina and Georgia / 「白人至上主義」の向こう側 : ノースカロライナ州及びジョージア州における劇『クランズマン(1905)』と『國民の創生(1915)』に対する南部白人たちの評価 / ハクジンシジョウシュギノムコウガワ : ノースカロライナシュウオヨビジョージアシュウニオケルゲキクランズマン 1905 トコクミンノソウセイ 1915 ニタイスルナンブハクジンタチノヒョウカ / 白人至上主義の向こう側 : ノースカロライナ州及びジョージア州における劇クランズマン1905と國民の創生1915に対する南部白人たちの評価三島(原) 恵実子, 三島恵実子, 原恵実子, Emiko Mishima Hara 07 March 2019 (has links) 昨今「白人至上主義」という単語が多用されているが、その定義は不明確なままである。なぜならば、たとえ人々の「白人至上主義」への認識に多少の差異があったとしても、結果がほぼ変わらないという見解が一般的であるからである。しかしながら本研究は、「白人至上主義」とは時代、場所、そして歴史的・社会的背景によって変容するものであると定義付けた。またある特定の「白人至上主義」を強調した演劇『クランズマン』、後の映画『國民の創生』、に対する南部白人の評価を分析することで、その概念を最も享受したであろう彼らが如何にその言葉の意味を定義し、またどのように保持し習慣づけていったのかを解明しようと試みたものである。 / This dissertation hypothesizes that white supremacy is a flexible ideology that changes depending on the location, the period, and historical as well as social conditions in which it is promoted. By examining and comparing the differences between the responses of white North Carolinians and white Georgians towards The Clansman in 1905 and The Birth of a Nation in 1915, this dissertation argues that even though we assume that Radical white supremacy seems to have covered the entire South during the Jim Crow era, and images and stories of supposed “black beast rapists” obscured social differences within the white group, there were a range of variable and sometimes competing ideologies among white supremacists. / 博士(アメリカ研究) / Doctor of Philosophy in American Studies / 同志社大学 / Doshisha University 白人至上主義南部史ホワイトネス・スタディーズ國民の創生クランズマンジョージア州ノースカロライナ州アトランタ人種暴動ウィルミントン人種暴動クー・クラックス・クラン人種アフリカ系アメリカ人ジム・クロウ融合政治ポピュリズム White Supreamcy Southern History Whiteness Studies The Birth of a Nation The Clansman Thomas Dixon Jr. Gerogia North Carolina Atlanta Race Riot Wilmington Race Riot Ku Klux Klan Race African American Jim Crow Fusion Governement Populism

Search results

Separation of Water and Fat Signal in Magnetic Resonance Imaging : Advances in Methods Based on Chemical Shift

The riotous presence in American literature and culture