Assessment of Terahertz Imaging for Excised Breast Cancer Tumors with Image Morphing

Abstract

This paper presents an image morphing algorithm for quantitative evaluation methodology of terahertz (THz) images of excised breast cancer tumors. Most current studies on the assessment of THz imaging rely on qualitative evaluation, and there is no established benchmark or procedure to quantify the THz imaging performance. The proposed morphing algorithm provides a tool to quantitatively align the THz image with the histopathology image. Freshly excised xenograft murine breast cancer tumors are imaged using the pulsed THz imaging and spectroscopy system in the reflection mode. Upon fixing the tumor tissue in formalin and embedding in paraffin, an FFPE tissue block is produced. A thin slice of the block is prepared for the pathology image while another THz reflection image is produced directly from the block. We developed an algorithm of mesh morphing using homography mapping of the histopathology image to adjust the alignment, shape, and resolution to match the external contour of the tissue in the THz image. Unlike conventional image morphing algorithms that rely on internal features of the source and target images, only the external contour of the tissue is used to avoid bias. Unsupervised Bayesian learning algorithm is applied to THz images to classify the tissue regions of cancer, fat, and muscles present in xenograft breast tumors. The results demonstrate that the proposed mesh morphing algorithm can provide more effective and accurate evaluation of THz imaging compared with existing algorithms. The results also showed that while THz images of FFPE tissue are highly in agreement with pathology images, challenges remain in assessing THz imaging of fresh tissue.

A Comprehensive Review on Food Applications of Terahertz Spectroscopy and Imaging

“…THz applications include security screening (García‐rial et al., ; Kaltenecker et al., ; (Liu, Zhong, Karpowicz, Chen, & Zhang, ), astronomical studies (Leisawitz et al., ), communication (Akyildiz, Miquel, & Han, ; Ergün & Sönmez, , nondestructive testing (Probst, Scheller, & Koch, ; Rutz, Koch, Khare, & Moneke, ), medical imaging (Bowman et al., ; Chavez, Bowman, Wu, Bailey, & El‐Shenawee, ; Dougherty et al., ; Fitzgerald et al., ; Sun et al., ; Truong, Fitzgerald, Fan, & Wallace, ), imaging of dental caries (Karagoz, Altan, & Kamburoglu, ; Ripoche, Reynard, Narcisse, & Roberts, ), pharmaceuticals (Markl, Dong, Li, & Zeitler, ; Pei et al., ; Sibik & Zeitler, ; Warnecke et al., , agricultural products (Liu et al., ; Liu, Liu, Hu, Yang, & Zheng, ; Luo, Zhu, Xu, & Cui, ; Nie, Qu, Lin, Dong, & He, ; Ogawa et al., ; Qin, Li, Chen, & Chen, ), food inspection and quality control (Ge, Jiang, Lian, & Zhang, ; Huang et al., , Shin, Choi, & Ok, ; Ok, Park, Kim, Chun, & Choi, ; Ok, Park, Lim, Jang, & Choi, ; Wang, Sun, & Pu, ; Yan, Liu, Qu, & Liu, ), environmental monitoring (Bigourd et al., ), and biosensing and label‐free monitoring of various biological processes (Yang et al., ). Full body THz scanners are installed in many airport checkpoints for detection of concealed objects and explosives.…”

“…THz applications include security screening (García-rial et al, 2018;Kaltenecker et al, 2018;(Liu, Zhong, Karpowicz, Chen, & Zhang, 2007), astronomical studies (Leisawitz et al, 2000), communication (Akyildiz, Miquel, & Han, 2014;Ergün & Sönmez, 2015, nondestructive testing (Probst, Scheller, & Koch, 2011;Rutz, Koch, Khare, & Moneke, 2006), medical imaging Chavez, Bowman, Wu, Bailey, & El-Shenawee, 2018;Dougherty et al, 2007;Fitzgerald et al, 2006;Sun et al, 2017;Truong, Fitzgerald, Fan, & Wallace, 2018), imaging of dental caries (Karagoz, Altan, & Kamburoglu, 2015;Ripoche, Reynard, Food applications of THz spectroscopy and imaging . .…”

Terahertz Imaging and Characterization Protocol for Freshly Excised Breast Cancer Tumors

“…As a result, THz imaging and spectroscopy has been used to classify and differentiate various tissue features such as water content to indicate burn damage and healing 4 , liver cirrhosis 5 , and cancer in excised tissues 6,7 . Cancer assessment in particular covers a broad range of potential clinical and surgical applications, and has been investigated for cancers of the brain 8 , liver 9 , ovaries 10 , gastrointestinal tract 11 , and breast 7,12,13,14,15,16,17,18,19 .…”

“…The objective of this work is to provide a guideline for THz application for freshly excised tissue using a commercial THz system. The protocol was developed on a THz imaging and spectroscopy system 26 for murine breast cancer tumors 13,17,19 and was extended to human surgical tissue obtained from biobanks 7,18 . While the protocol was generated for breast cancer, the same concepts can be applied to similar THz imaging systems and other types of solid-tumor cancers that are treated with surgery where success depends on margin assessment 27 .…”

Electrically Reconfigurable Micromirror Array for Direct Spatial Light Modulation of Terahertz Waves over a Bandwidth Wider Than 1 THz

“…Other substances allow their identification due to strong absorption in the terahertz frequency band. For these reasons, terahertz technology is potentially suited for spectroscopy and imaging of concealed substances in security screening 2,3 ,quality control 4–6 and bio-medical applications 7–9 .…”