Date of Graduation

8-2014

Document Type

Thesis

Degree Name

Master of Science in Electrical Engineering (MSEE)

Degree Level

Graduate

Department

Electrical Engineering

Advisor/Mentor

El-Shenawee, Magda O.

Committee Member

Zaharoff, David A.

Second Committee Member

McCann, Roy A.

Keywords

Biomedical Imaging; Breast Cancer; Spectroscopy; Terahertz

Abstract

This thesis presents experimental results of terahertz imaging and spectroscopy techniques to analyze excised breast cancer tissue. The pulsed terahertz system at the University of Arkansas was used to assess formalin-fixed, paraffin-embedded breast cancer tissue obtained from 22, 40, and 46 year old patients. The tissue for this research was sliced to relatively thin sections of 10 μm thick and mounted on glass slides. Terahertz reflection time and frequency domain images of the breast cancer tissue were then obtained and compared to histopathology slides from the same patient. Results showed good correlation between the reflection images and histopathology slides for the 40 and 46 year old patients. However, there were inconsistent results for the 22 year old patient, possibly due to the age of the patient. The measurements obtained from reflection imaging were also compared to the theoretical solution of the reflection coefficient. The theoretical solution used tissue properties found via terahertz spectroscopy. Thus the strong correlation of this comparison indicated good agreement between the two techniques.

Standard electromagnetic techniques were used to formulate the expression for spectroscopy of a single dielectric layer, and the results were validated against literature for the glass slide. Then the formulation was developed to find the properties of tissue on a glass slide via terahertz spectroscopy. A large number of points across the samples were measured to find the electrical properties of infiltrating ductal carcinoma and fibroglandular tissue up to 1.2 THz that best matched the analytical solution. Statistical analysis of the spectroscopy data showed distinct characteristics between the cancerous and normal tissue in the 40 and 46 year old patient consistent with the terahertz reflection imaging. However, there was a wide margin of error in these measurements due to the large absorption in the glass slide. Overall, terahertz was found to have a strong potential for applications with breast cancer tissue.

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