Abstract-Concentration analysis of breast tissue phantoms with terahertz spectroscopy

Bao C. Q. Truong, Anthony J. Fitzgerald, Shuting Fan, and Vincent P. Wallace

https://www.osapublishing.org/boe/abstract.cfm?uri=boe-9-3-1334#top

Terahertz imaging has been previously shown to be capable of distinguishing normal breast tissue from its cancerous form, indicating its applicability to breast conserving surgery. The heterogeneous composition of breast tissue is among the main challenges to progressing this potential research towards a practical application. In this paper, two concentration analysis methods are proposed for analyzing phantoms mimicking breast tissue. The dielectric properties and the double Debye parameters were used to determine the phantom composition. The first method is wholly based on the conventional effective medium theory while the second one combines this theoretical model with empirical polynomial models. Through assessing the accuracy of these methods, their potential for application to quantifying breast tissue pathology was confirmed.

© 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Abstract-Use of a handheld terahertz pulsed imaging device to differentiate benign and malignant breast tissue

Maarten R. Grootendorst, Anthony J. Fitzgerald, Susan G. Brouwer de Koning, Aida Santaolalla, Alessia Portieri, Mieke Van Hemelrijck, Matthew R. Young, Julie Owen, Massi Cariati, Michael Pepper, Vincent P. Wallace, Sarah E. Pinder, and Arnie Purushotham

https://www.osapublishing.org/boe/abstract.cfm?uri=boe-8-6-2932

Since nearly 20% of breast-conserving surgeries (BCS) require re-operation, there is a clear need for developing new techniques to more accurately assess tumor resection margins intraoperatively. This study evaluates the diagnostic accuracy of a handheld terahertz pulsed imaging (TPI) system to discriminate benign from malignant breast tissue ex vivo. Forty six freshly excised breast cancer samples were scanned with a TPI handheld probe system, and histology was obtained for comparison. The image pixels on TPI were classified using (1) parameters in combination with support vector machine (SVM) and (2) Gaussian wavelet deconvolution in combination with Bayesian classification. The results were an accuracy, sensitivity, specificity of 75%, 86%, 66% for method 1, and 69%, 87%, 54% for method 2 respectively. This demonstrates the probe can discriminate invasive breast cancer from benign breast tissue with an encouraging degree of accuracy, warranting further study.

© 2017 Optical Society of America

Abstract- Use of Finite Difference Time Domain Simulations and Debye Theory for Modelling the Terahertz Reflection Response of Normal and Tumour Breast Tissue

• Anthony J. Fitzgerald,
 
• Emma Pickwell-MacPherson,
 
• Vincent P. Wallace mail

• Published: July 10, 2014
• DOI: 10.1371/journal.pone.0099291

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0099291?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+plosone%2FPLoSONE+(PLOS+ONE+Alerts%3A+New+Articles)

The aim of this work was to evaluate the capabilities of Debye theory combined with Finite Difference Time Domain (FDTD) methods to simulate the terahertz (THz) response of breast tissues. Being able to accurately model breast tissues in the THz regime would facilitate the understanding of image contrast parameters used in THz imaging of breast cancer. As a test case, the model was first validated using liquid water and simulated reflection pulses were compared to experimental measured pulses with very good agreement (p = 1.00). The responses of normal and cancerous breast tissues were simulated with Debye properties and the correlation with measured data was still high for tumour (p = 0.98) and less so for normal breast (p = 0.82). Sections of the time domain pulses showed clear differences that were also evident in the comparison of pulse parameter values. These deviations may arise from the presence of adipose and other inhomogeneities in the breast tissue that are not accounted for when using the Debye model. In conclusion, the study demonstrates the power of the model for simulating THz reflection imaging; however, for biological tissues extra Debye terms or a more detailed theory may be required to link THz image contrast to physiological composition and structural changes of breast tissue associated with differences between normal and tumour tissues.

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Citation: Fitzgerald AJ, Pickwell-MacPherson E, Wallace VP (2014) Use of Finite Difference Time Domain Simulations and Debye Theory for Modelling the Terahertz Reflection Response of Normal and Tumour Breast Tissue. PLoS ONE 9(7): e99291. doi:10.1371/journal.pone.0099291

Editor: Irene Georgakoudi, Tufts University, United States of America

Received: January 22, 2014; Accepted: May 13, 2014; Published: July 10, 2014