Factors Affecting Image Quality in Near-field Ultra-wideband Radar Imaging for Biomedical Applications

Date
2015-09-01
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Abstract
Near-field ultra-wideband radar imaging has potential as a new breast imaging modality. While a number of reconstruction algorithms have been published with the goal of reducing undesired responses or clutter, an in-depth analysis of the dominant sources of clutter has not been conducted. In this thesis, time domain radar image reconstruction is demonstrated to be equivalent to frequency domain synthetic aperture radar. This reveals several assumptions inherent to the reconstruction algorithm related to radial spreading, point source antennas, and the independent summation of point scatterers. Each of these assumptions is examined in turn to determine which has the greatest impact on the resulting image quality and interpretation. In addition, issues related to heterogeneous and dispersive media are addressed. Variations in imaging parameters are tested by observing their influence on the system point spread function. Results are then confirmed by testing on simple and detailed simulation models, followed by data acquired from human volunteers. Recommended parameters are combined into a new imaging operator that is demonstrated to generate results comparable to a more accurate signal model, but with a 50 fold improvement in computational efficiency. Finally, the most significant factor affecting image quality is determined to be the estimate of tissue properties used to form the image.
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Keywords
Engineering--Biomedical, Engineering--Electronics and Electrical
Citation
Curtis, C. (2015). Factors Affecting Image Quality in Near-field Ultra-wideband Radar Imaging for Biomedical Applications (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/26144