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You searched for +publisher:"Georgia Tech" +contributor:("Xiaoping P. Hu"). Showing records 1 – 3 of 3 total matches.

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Georgia Tech

1. Sechopoulos, Ioannis. Investigation of physical processes in digital x-ray tomosynthesis imaging of the breast.

Degree: PhD, Biomedical Engineering, 2007, Georgia Tech

Early detection is one of the most important factors in the survival of patients diagnosed with breast cancer. For this reason the development of improved screening mammography methods is one of primary importance. One problem that is present in standard planar mammography, which is not solved with the introduction of digital mammography, is the possible masking of lesions by normal breast tissue because of the inherent collapse of three-dimensional anatomy into a two-dimensional image. Digital tomosynthesis imaging has the potential to avoid this effect by incorporating into the acquired image information on the vertical position of the features present in the breast. Previous studies have shown that at an approximately equivalent dose, the contrast-detail trends of several tomosynthesis methods are better than those of planar mammography. By optimizing the image acquisition parameters and the tomosynthesis reconstruction algorithm, it is believed that a tomosynthesis imaging system can be developed that provides more information on the presence of lesions while maintaining or reducing the dose to the patient. Before this imaging methodology can be translated to routine clinical use, a series of issues and concerns related to tomosynthesis imaging must be addressed. This work investigates the relevant physical processes to improve our understanding and enable the introduction of this tomographic imaging method to the realm of clinical breast imaging. The processes investigated in this work included the dosimetry involved in tomosynthesis imaging, x-ray scatter in the projection images, imaging system performance, and acquisition geometry. A comprehensive understanding of the glandular dose to the breast during tomosynthesis imaging, as well as the dose distribution to most of the radiosensitive tissues in the body from planar mammography, tomosynthesis and dedicated breast computed tomography was gained. The analysis of the behavior of x-ray scatter in tomosynthesis yielded an in-depth characterization of the variation of this effect in the projection images. Finally, the theoretical modeling of a tomosynthesis imaging system, combined with the other results of this work was used to find the geometrical parameters that maximize the quality of the tomosynthesis reconstruction. Advisors/Committee Members: Andrew Karellas, John N. Oshinski, Xiaoping P. Hu, Carl J. D’Orsi and Ernest V. Garcia.

Subjects/Keywords: Breast; Radiography; Diagnostic imaging; Three-dimensional imaging in medicine; Radiation dosimetry

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APA (6th Edition):

Sechopoulos, I. (2007). Investigation of physical processes in digital x-ray tomosynthesis imaging of the breast. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/22589

Chicago Manual of Style (16th Edition):

Sechopoulos, Ioannis. “Investigation of physical processes in digital x-ray tomosynthesis imaging of the breast.” 2007. Doctoral Dissertation, Georgia Tech. Accessed December 03, 2020. http://hdl.handle.net/1853/22589.

MLA Handbook (7th Edition):

Sechopoulos, Ioannis. “Investigation of physical processes in digital x-ray tomosynthesis imaging of the breast.” 2007. Web. 03 Dec 2020.

Vancouver:

Sechopoulos I. Investigation of physical processes in digital x-ray tomosynthesis imaging of the breast. [Internet] [Doctoral dissertation]. Georgia Tech; 2007. [cited 2020 Dec 03]. Available from: http://hdl.handle.net/1853/22589.

Council of Science Editors:

Sechopoulos I. Investigation of physical processes in digital x-ray tomosynthesis imaging of the breast. [Doctoral Dissertation]. Georgia Tech; 2007. Available from: http://hdl.handle.net/1853/22589


Georgia Tech

2. Suryanarayanan, Sankararaman. Design, Development, and Characterization of a Prototype Digital Mammography System.

Degree: PhD, Biomedical Engineering, 2006, Georgia Tech

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. Advisors/Committee Members: Andrew Karellas, Ph.D. (Committee Chair), Ernest V. Garcia, Ph.D. (Committee Member), John N. Oshinski (Committee Member), Xiaoping P. Hu, Ph.D. (Committee Member).

Subjects/Keywords: Breast cancer; Contrast-detail characteristics; Digital mammography; High-resolution digital mammography systems; Integrated image processing; Image processing Digital techniques; Breast Radiography

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Suryanarayanan, S. (2006). Design, Development, and Characterization of a Prototype Digital Mammography System. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/14515

Chicago Manual of Style (16th Edition):

Suryanarayanan, Sankararaman. “Design, Development, and Characterization of a Prototype Digital Mammography System.” 2006. Doctoral Dissertation, Georgia Tech. Accessed December 03, 2020. http://hdl.handle.net/1853/14515.

MLA Handbook (7th Edition):

Suryanarayanan, Sankararaman. “Design, Development, and Characterization of a Prototype Digital Mammography System.” 2006. Web. 03 Dec 2020.

Vancouver:

Suryanarayanan S. Design, Development, and Characterization of a Prototype Digital Mammography System. [Internet] [Doctoral dissertation]. Georgia Tech; 2006. [cited 2020 Dec 03]. Available from: http://hdl.handle.net/1853/14515.

Council of Science Editors:

Suryanarayanan S. Design, Development, and Characterization of a Prototype Digital Mammography System. [Doctoral Dissertation]. Georgia Tech; 2006. Available from: http://hdl.handle.net/1853/14515


Georgia Tech

3. Glaus, Charles R. M. Development and analysis of radiolabeled magnetic nanoparticles for positron emission tomography and magnetic resonance imaging.

Degree: PhD, Biomedical Engineering, 2008, Georgia Tech

Nanoparticles possess unique characteristics that make them well suited for molecular imaging. Particles can be synthesized in a systematic fashion with tight control over diameter and surface chemistry. Contrary to existing gadolinium-based MRI contrast agents, nanoparticle MRI contrast agents circulate in the blood for long periods of time, offer higher sensitivity, and exhibit little known toxicity. The qualities of nanoparticles are also well suited to the design of PET probes. Because of their large surface area nanoparticles can be radiolabeled at high specific activity, increasing the sensitivity of detection as well as the payload of therapeutic isotopes. The work presented here focuses on the development and biological application of novel radiolabeled magnetic nanoparticles for multimodal PET/MRI imaging. The nanoparticle probes contained crystalline iron oxide cores capable of producing strong MRI contrast. Cores were coated with either a micelle composed of functionalized PEGylated lipids, or a cross-linked dextran shell modified with heterobifuntional PEG polymers. For PET imaging, magnetic nanoparticles were labeled with the radionuclide 64Cu. Copper‐64 is a cyclotron produced positron emitter used for PET imaging. With a 12.7 hour half-life, 64Cu can be used to image particles in vivo for up to 48 hr and can be used to evaluate ex vivo biodistribution for 72 hours. 64Cu nuclides also undergo β‐ decay, making it a useful isotope for radiotherapy. Nanoparticles were labeled with 64Cu and PET and MRI contrast and evaluated using phantoms. Pharmacokinetic information was measured using in vivo small animal PET/CT and ex vivo biodistribution at multiple time points. Particles were targeted to the angiogenesis marker αvβ3 integrin using a cyclized arginine-glycine-aspartic acid (RGD) peptide with high affinity for αvβ3 and tested in two tumor models. A unilateral tumor model was constructed using the αvβ3-positive U87MG glioblastoma line, and a bilateral model was constructed using the M21 (αvβ3 positive) and M21L (αvβ3 negative) melanoma lines. In vivo PET/CT and MRI showed that targeted nanoparticles produced both PET and MRI contrast in tumors. In conclusion, we report the development of magnetic nanoparticles for dual‐PET/MR imaging. These findings provide insight into the design and development of future multimodality PET/MRI probes. Advisors/Committee Members: Gang Bao (Committee Chair), Kurt D. Pennell (Committee Member), Mark M. Goodman (Committee Member), Xiaoping P. Hu (Committee Member), Yadong Wang (Committee Member).

Subjects/Keywords: Cancer; Nanotechnology; Nuclear; Integrin; Tumor; Molecular imaging; Diagnostic imaging; Tomography, Emission; Nanoparticles; Positrons Emission; Imaging systems; Radiolabeling

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Glaus, C. R. M. (2008). Development and analysis of radiolabeled magnetic nanoparticles for positron emission tomography and magnetic resonance imaging. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/31692

Chicago Manual of Style (16th Edition):

Glaus, Charles R M. “Development and analysis of radiolabeled magnetic nanoparticles for positron emission tomography and magnetic resonance imaging.” 2008. Doctoral Dissertation, Georgia Tech. Accessed December 03, 2020. http://hdl.handle.net/1853/31692.

MLA Handbook (7th Edition):

Glaus, Charles R M. “Development and analysis of radiolabeled magnetic nanoparticles for positron emission tomography and magnetic resonance imaging.” 2008. Web. 03 Dec 2020.

Vancouver:

Glaus CRM. Development and analysis of radiolabeled magnetic nanoparticles for positron emission tomography and magnetic resonance imaging. [Internet] [Doctoral dissertation]. Georgia Tech; 2008. [cited 2020 Dec 03]. Available from: http://hdl.handle.net/1853/31692.

Council of Science Editors:

Glaus CRM. Development and analysis of radiolabeled magnetic nanoparticles for positron emission tomography and magnetic resonance imaging. [Doctoral Dissertation]. Georgia Tech; 2008. Available from: http://hdl.handle.net/1853/31692

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