Polarimetric Terahertz Transmission Imaging of Crystal Quartz Sample.

This paper investigates polarimetric terahertz time domain transmission imaging aiming at enhancing the detection of different regions on the same sample. Here, x-cut quartz crystal adjacent to quartz glass are utilized to compose a sample that hypothetically mimics breast tumor of cancerous and healthy regions, respectively. The obtained images establish a potential advantage of polarimetric terahertz imaging for future use in imaging excised breast cancer tumors.

Visual Enhancement and Semantic Segmentation of Murine Tissue Scans with Pulsed THz Spectroscopy.

Semantic Artificial Intelligence has certain qualities that are advantageous for deep learning-based medical imaging tasks. Medical images can be augmented by injecting semantic context into the underlying classification mechanism, increasing the information density of the scan and ultimately can provide more trust in the result. This work considers an application of semantic AI to segment tissue types from excised breast tumors imaged with pulsed terahertz (THz)-an emerging imaging technology.

Deep Learning Classification of Breast Cancer Tissue from Terahertz Imaging Through Wavelet Synchro-Squeezed Transformation and Transfer Learning.

Terahertz imaging and spectroscopy is an exciting technology that has the potential to provide insights in medical imaging. Prior research has leveraged statistical inference to classify tissue regions from terahertz images. To date, these approaches have shown that the segmentation problem is challenging for images of fresh tissue and for tumors that have invaded muscular regions.

Hyperspectral terahertz imaging and optical clearance for cancer classification in breast tumor surgical specimen.

We investigate the enhancement in terahertz (THz) images of freshly excised breast tumors upon treatment with an optical clearance agent. The hyperspectral imaging and spectral classifications are used to quantitatively demonstrate the image enhancement. Glycerol solution with 60% concentration is applied to excised breast tumor specimens for various time durations to investigate the effectiveness on image enhancement.

Mammary tumors in Sprague Dawley rats induced by N-ethyl-N-nitrosourea for evaluating terahertz imaging of breast cancer.

The objective of this study is to quantitatively evaluate terahertz (THz) imaging for differentiating cancerous from non-cancerous tissues in mammary tumors developed in response to injection of N-ethyl-N-nitrosourea (ENU) in Sprague Dawley rats. While previous studies have investigated the biology of mammary tumors of this model, the current work is the first study to employ an imaging modality to visualize these tumors. A pulsed THz imaging system is utilized to experimentally collect the time-domain reflection signals from each pixel of the rat's excised tumor.

Breast Cancer Detection with Low-dimension Ordered Orthogonal Projection in Terahertz Imaging.

This paper proposes a new dimension reduction algorithm based on low-dimension ordered orthogonal projection (LOOP), which is used for cancer detection with terahertz (THz) images of freshly excised human breast cancer tissues. A THz image can be represented by a data cube with each pixel containing a high dimension spectrum vector covering several THz frequencies, where each frequency represents a different dimension in the vector. The proposed algorithm projects the high-dimension spectrum vector of each pixel within the THz image into a low-dimension subspace that contains the majority of the unique features embedded in the image.

Terahertz Imaging and Characterization Protocol for Freshly Excised Breast Cancer Tumors.

This manuscript presents a protocol to handle, characterize, and image freshly excised human breast tumors using pulsed terahertz imaging and spectroscopy techniques. The protocol involves terahertz transmission mode at normal incidence and terahertz reflection mode at an oblique angle of 30°. The collected experimental data represent time domain pulses of the electric field.

Pulsed Terahertz Reflection Imaging of tumors in a spontaneous model of breast cancer.

We report the use of reflection-mode terahertz (THz) imaging in a transgenic mouse model of breast cancer. Unlike tumor xenografts that are grown from established cell lines, these tumors were spontaneously generated in the mammary fat pad of mice, and are a better representation of human breast cancer. THz imaging results from 7 tumors that recapitulate the compartmental complexity of breast cancer are presented here.

Terahertz tomographic imaging of freshly excised human breast tissues.

Terahertz imaging and spectroscopy characterization of freshly excised breast cancer tumors are presented in the range 0.15 to 3.5 THz.

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

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.

Cancer detection in excised breast tumors using terahertz imaging and spectroscopy.

Terahertz imaging and spectroscopy has demonstrated a potential for differentiating tissue types of excised breast cancer tumors. Pulsed terahertz technology provides a broadband frequency range from 0.1 THz to 4 THz for detecting cancerous tissue.

A Phantom Study of Terahertz Spectroscopy and Imaging of Micro- and Nano-diamonds and Nano-onions as Contrast Agents for Breast Cancer.

THz imaging is effective in distinguishing between cancerous, healthy, and fatty tissues in breast tumors, but a challenge remains in the contrast between cancerous and fibroglandular (healthy) tissues. This work investigates carbon-based nanoparticles as potential contrast agents for terahertz imaging of breast cancer. Microdiamonds, nanodiamonds, and nanometer-scale onion-like carbon are characterized with terahertz transmission spectroscopy in low-absorption backgrounds of polydimethylsiloxane or polyethylene.

Pulsed terahertz imaging of breast cancer in freshly excised murine tumors.

This paper investigates terahertz (THz) imaging and classification of freshly excised murine xenograft breast cancer tumors. These tumors are grown via injection of E0771 breast adenocarcinoma cells into the flank of mice maintained on high-fat diet. Within 1 h of excision, the tumor and adjacent tissues are imaged using a pulsed THz system in the reflection mode.

Terahertz transmission vs reflection imaging and model-based characterization for excised breast carcinomas.

This work presents experimental and analytical comparison of terahertz transmission and reflection imaging modes for assessing breast carcinoma in excised paraffin-embedded human breast tissue. Modeling for both transmission and reflection imaging is developed. The refractive index and absorption coefficient of the tissue samples are obtained.

Biopotential signals of breast cancer versus tumor types and proliferation stages.

Clinical studies have shown compelling data of elevated biopotential signals recorded noninvasively from the breasts of women with breast cancer. While these data are compelling and show a strong potential for use in the noninvasive early detection of breast cancer, there remains significant knowledge gaps which must be addressed before this technology can be routinely used for breast cancer detection. A diffusion-drift model is developed to study the spatial and temporal characteristics of the biopotential signals of breast tumors taking into account the morphology and cell division stages.

Review of electromagnetic techniques for breast cancer detection.

Breast cancer is anticipated to be responsible for almost 40,000 deaths in the USA in 2011. The current clinical detection techniques suffer from limitations which motivated researchers to investigate alternative modalities for the early detection of breast cancer. This paper focuses on reviewing the main electromagnetic techniques for breast cancer detection.

Modeling biopotential signals and current densities of multiple breast cancerous cells.

This study presents a model to simulate the electrophysiological activities of multiple Michigan Cancer Foundation-7 (MCF-7) cells, the most studied breast cancer cell line. The intercellular spacing of MCF-7 cells is estimated using the effective diffusion coefficient. Nonuniform finite-difference discretization is implemented to accommodate for the contrast in size between the intercellular spacing and the cell dimension.

Modeling electrical activities of a growing breast cancerous cell based on a semiconductor approach.

A two dimensional diffusion-drift model is developed to simulate the electrical activities of a breast cancerous cell during the hyperpolarization which occurs at the G1/S transition. The model focuses on calculating the temporal and the spatial patterns of the electric current densities and biopotentials generated at the cell boundary and its surroundings. Different durations for the hyperpolarization phase were studied.

Diffusion-drift modeling of a growing breast cancerous cell.

This paper presents a 2-D model to calculate the electric current densities and the biopotential differences generated due to a breast cancerous cell during the hyperpolarization of the G1/synthesis (G1/S) transition. The proposed model is based on semiconductor diffusion-drift analysis, and aims to understand the biophysics associated with growing breast cancerous cells. The effect of the duration of the G1/S transition, and the diffusivity and the mobility of the cancerous cell boundary is investigated.

Computational model of ductal carcinoma in situ: the effects of contact inhibition on pattern formation.

The computational model presented in this paper focuses on modeling ductal carcinoma in situ (DCIS), which is the most commonly detected preinvasive form of breast cancer. The model aims to understand the biological mechanisms and resultant growth dynamics of DCIS. The cellular automaton model based on observed phenotypic characteristics of DCIS emphasize the important role of contact inhibition on lesion pattern formation.

Spherical harmonics microwave algorithm for shape and location reconstruction of breast cancer tumor.

A reconstruction algorithm to simultaneously estimate the shape and location of three-dimensional breast cancer tumor is presented and its utility is analyzed. The approach is based on a spherical harmonic decomposition to capture the shape of the tumor. We combine a gradient descent optimization method with a direct electromagnetic solver to determine the coefficients in the harmonic expansion as well as the coordinates of the center of the tumor.

Resonant spectra of malignant breast cancer tumors using the three-dimensional electromagnetic fast multipole model.

This paper presents an intensive numerical study of the resonance scattering of malignant breast cancer tumors. The three-dimensional electromagnetic model, based on the equivalence theorem, is used to obtain induced electric and magnetic currents on breast and tumor surfaces. The results show that the nonspherical malignant tumor can be characterized, based on its spectra, regardless of orientation, incident polarization, or incident or scattered directions.

Remote sensing of penetrable objects buried beneath two-dimensional random rough surfaces by use of the Mueller matrix elements.

The modified Mueller matrix elements for electromagnetic scattering from penetrable objects buried under two-dimensional random rough surfaces are investigated. This matrix relates the incident to the scattered waves, and it contains different combinations of the fully polarimetric scattering matrix elements. The statistical average of each Mueller matrix element is computed on the basis of the Monte Carlo simulations by exploiting the speed of the three-dimensional steepest-descent fast multipole method.