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Title: The development of a near infrared time resolved imaging system and the assessment of the methodology for breast imaging
Author: Hall, David Jonathan
Awarding Body: University of London
Current Institution: University College London (University of London)
Date of Award: 1996
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The aim of my Ph.D. research was the development and assessment of a time resolved near infrared (NIR) system for imaging through highly scattering media, with a view to its potential as a future breast imaging modality. This was motivated by the desire to produce a breast imaging system using harmless doses of NIR radiation as a more effective, less expensive and safer alternative to x-ray mammography. The principal components of the time resolved NIR system are a picosecond pulse laser and a streak camera to record transmitted intensity as a function of time. My Ph.D. research has involved the development of an automation program to control the system, including two-dimensional translation of the object being imaged, data collection, and laser power monitoring. The implementation of the automation program increased the data acquisition rate by approximately a factor of ten. This enabled experiments to be performed which had previously been prohibited by time constraints. Several different phantoms have been manufactured and imaged in order to assess the breast imaging potential of the approach. These have included phantoms with optical properties similar to breast tissue, edge-phantoms to evaluate the achievable spatial resolution, and phantoms with several embedded inhomogeneities of differing optical properties to evaluate the achievable contrast. Data processing software was also developed to produce images of the phantoms. The time-gating principle has been employed to generate images which are superior to previous conventional CW transillumination methods. Further improvement in the images has been obtained by using a novel technique known as temporal extrapolation. Overall, the research has demonstrated the success of the time resolved methodology to obtain images of breast-like phantoms. Furthermore, as a consequence of the research a clinical time resolved breast imaging system is currently being constructed at UCL.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: Radiobiology & radiation biology