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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

Energy mapping of scattered protons within a gas target

Publicover, Julia Georgina. 10 April 2008 (has links)
No description available.
2

Objective image quality assessment for positron emission tomography : planar (2D) and volumetric (3D) human and model observer studies /

Kim, Jae-Seung. January 2003 (has links)
Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (leaves 98-103).
3

Impact of time-of-flight technology on PET/CT image quality and SUV quantitation

Lau, Yu-ching., 劉禹政. January 2012 (has links)
Time-of-flight technology (TOF) is at the leading edge of advancements in PET/CT imaging, and is made possible due to the availability of new scanner design, scintillating materials and fast computers. The location of annihilation is estimated according to the time difference between scintillation events produced by two 511KeV gamma photons travelling in opposite directions. The additional information is incorporated into image reconstruction to suppress noise propagation and increase signal-to-noise ratio. As shown in previous studies, these properties can be translated in to clinical usage to obtain improved image quality using the same acquisition time, while also enhancing image quality under shortened acquisition or reduce tracer dosage injected to patients. Semi-quantification units such as standardized uptake value (SUV) and standard deviation (SD) are measured on static PET images and are widely used clinically to quantify the rate of cell metabolism. Signal-to-noise ratio (SNR) and coefficient of variation (CV) can be calculated to assess image quality. However, these parameters depend on image reconstruction and are therefore expected to change with the use of TOF. Breath holding (BH) PET/CT imaging protocol has been suggested to help evaluation of lesions affected by respiratory motion. However, the PET image quality is significantly degraded since the acquisition time is shortened (e.g. 30 seconds). Noise on BH PET image may cause inaccuracy in semi-quantitation and difficulties in visual assessment. TOF can be applied to improve the image quality and enhance subtle lesions, thus helping the characterization of small lung nodules (SLN) with potential clinical impact. This thesis aims to evaluate the impact of TOF on PET image quality and the quantification of SUV in clinical practice. Firstly, the performance of a TOF PET/CT scanner is tested using a phantom mimicking human body trunk with ‘lesions’. Using the same acquisition time (2 minutes/bed), TOF images outperformed conventional images in terms of lesion detectability and background uniformity, especially for small spheres and under low lesion-to-background ratio. Moreover, TOF images acquired using a shorter scan time (1.5 minutes/bed) also maintained acceptable image quality. In the second study, the influence on SUV measurement and image quality (in terms of CV) are evaluated in twelve normal organ structures on whole-body FDG PET/CT images. TOF significantly decreased SUVmax (9/12) and SUVmean (8/12) among the twelve normal organ structures investigated. It also improved the image quality, particularly in solid organs in the abdomen. The combined utility of TOF and BH PET/CT imaging protocol for the detection of SLN is demonstrated in the third study. Lesions showing PET activity, which were misaligned with anatomical location on CT, had higher SUVmax and comparable SNR on BH images. PET/CT fusion was also markedly improved. The additional use of TOF further enhanced lesion detection and improved SNR. The results demonstrate the benefits of using TOF in clinical PET/CT, including its advantage with breath holding PET/CT imaging. This information not only offers a better understanding of this increasingly popular technology in modern PET/CT scanners, but also highlights its potential applications in clinical practice. / published_or_final_version / Diagnostic Radiology / Master / Master of Philosophy
4

Single photon emission computed tomography performance assessment, development and clinical applications /

Gillen, Gerard J. January 1990 (has links)
Thesis (Ph.D.) - University of Glasgow, 1990. / BLL. DX192708. Ph.D. thesis submitted to the Department of Clinical Physics and Bio-Engineering, University of Glasgow, 1990. Includes bibliographical references.
5

Maximum likelihood-expectation maximum reconstruction with limited dataset for emission tomography

Patel, Rahul. January 2007 (has links)
Thesis (M.S.)--University of Akron, Dept. of Biomedical Engineering, 2007. / "May, 2007." Title from electronic thesis title page (viewed 04/26/2009) Advisor, Dale Mugler; Co-Advisor, Anthony Passalaqua; Committee member, Daniel Sheffer; Department Chair, Daniel Sheffer; Dean of the College, George K. Haritos; Dean of the Graduate School, George R. Newkome. Includes bibliographical references.
6

Quantitative functional imaging using dynamic positron computed tomography and rapid parameter estimation techniques

Koeppe, Robert Allen. January 1984 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1984. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 214-222).
7

A dynamic technique for the quantitation of oxygen utilization rates using positron emission tomography

Hutchins, Gary Dwight. January 1984 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1984. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 205-213).
8

Respiratory motion correction for positron emission tomography

Dikaios, Nikolaos January 2012 (has links)
No description available.
9

A technique for improving data acquisition and resolution in positron emission tomography /

Dagher, Alain. January 1985 (has links)
No description available.
10

Quantitation in positron emission tomography

Strother, S. C. (Steven Charles), 1955- January 1986 (has links)
No description available.

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