Photoacoustic tomography for prostate imaging by transurethral illumination
department or school: Applied Science, Faculty of
department or school: Biomedical Engineering, School of
data provider: DSpace
degree campus: UBCV
creator: Ai, Min
issued: 2020-03-23T19:03:57Z
issued: 2020
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: Photoacoustic tomography (PAT) is a hybrid imaging modality that combines optical excitation and acoustic detection and overcomes the optical diffusion limit in tissue. Taking the advantages of deep penetration and high resolution, PAT is widely applied in biosciences. In prostate imaging, several PAT systems have been demonstrated to be capable of showing distinct photoacoustic (PA) contrast from malignant tissue or angiogenesis-related to prostate cancer. In this thesis, I explore the potential of applying PAT with transurethral illumination for prostate imaging. Challenges in translating PAT system to clinical imaging for prostate include the lack of sufficient local fluence for deep tissue penetration, risk of over irradiation near the laser-tissue contact surface and limited image reconstruction quality caused by the limited detection view and noisy PA signal. In this thesis, systematic design, optimization, and application of a PAT system with transurethral illumination are conducted. A fiber coupling scheme with a beam homogenizer is demonstrated for coupling high energy pulses in a single multimode fiber, achieved by using a cross cylindrical lens array. The peak power on the fiber tip surface is reduced and thus enhances the coupling performance. Recorded high pulse energy is achieved with high coupling efficiency as well. The high pulse energy can enable deep imaging depth in tissue. With high-energy pulses delivered by the multimode fiber, a transurethral illumination probe is designed, which can illuminate the prostate from the urethra. A parabolic cylindrical mirror reflects the light emitted from the diffusing fiber to achieve a parallel side illumination with doubled fluence. This design is optimized for both high energy pulse illumination and maintaining the laser fluence below the safety limit in tissue. As the detection view for prostate imaging is limited, a variance-reduced stochastic gradient descent (VR-SGD) algorithm is developed to improve th…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/73788
note: PHOTOACOUSTIC TOMOGRAPHY FOR PROSTATE IMAGING BY TRANSURETHRAL ILLUMINATION by Min Ai B.Sc., Harbin Institute of Technology, 2011 M.Sc., Harbin Institute of Technology, 2013 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Biomedical Engineering) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) March 2020 © Min Ai, 2020 ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, the dissertation entitled: Photoacoustic tomography for prostate imaging by transurethral illumination submitted by Min Ai in partial fulfillment of the requirements for the degree of Doctor of Philosophy in The faculty of graduate and postdoctoral studies (Biomedical Engineering) Examining Committee: Prof. Shuo Tang Supervisor Prof. Septimiu E. Salcudean Supervisory Committee Member Prof. Robert Rohling Supervisory Committee Member Prof. Jane Z. Wang University Examiner Prof. Keng Chou University Examiner Additional Supervisory Committee Members: Prof. Purang Abolmaesumi Supervisory Committee Member Supervisory Committee Member iii Abstract Photoacoustic tomography (PAT) is a hybrid imaging modality that combines optical excitation and acoustic detection and overcomes the optical diffusion limit in tissue. Taking the advantages of deep penetration and high resolution, PAT is widely applied in biosciences. In prostate imaging, several PAT systems have been demonstrated to be capable of showing distinct photoacoustic (PA) contrast from malignant tissue or angiogenesis-related to prostate cancer. In this thesis, I explore the potential of applying PAT with transurethral illumination for prostate imaging. Challenges in translating PAT system to clinical imaging for prostate include the lack of sufficient local fluence for deep tissue penetration, risk of over irradiation near the laser-tissue contact surface and li…
has type: Thesis/Dissertation
date issued: 2020-05
is shown at: 10.14288/1.0389619
language: eng
degree discipline: Biomedical Engineering
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/73788