Prof. Magda O. El-Shenawee Profile

Prof. Magda O. El-Shenawee

Professor of Electrical Engineering at Univ of Arkansas

SPIE Involvement:

Author

Publications (20)

SPIE Journal Paper | 12 January 2022

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

Nagma Vohra, Haoyan Liu, Alexander H. Nelson, Keith Bailey, Magda El-Shenawee

JMI, Vol. 9, Issue 01, 014002, (January 2022) https://doi.org/10.1117/12.10.1117/1.JMI.9.1.014002

KEYWORDS: Tissues, Terahertz radiation, Cancer, Tumors, Pathology, Collagen, Hyperspectral imaging, Absorption, Breast, Image classification

Read Abstract +

Purpose: 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. Approach: THz reflection spectroscopy is utilized to obtain the absorption coefficient and the index of refraction of untreated and glycerol-treated tissues at each frequency up to 3 THz. Two classifiers, spectral angular mapping (SAM) based on several kernels and Euclidean minimum distance (EMD) are implemented to evaluate the effectiveness of the treatment. The testing raw data is obtained from five breast cancer specimens: two untreated specimens and three specimens treated with glycerol solution for 20, 40, or 60 min. All tumors used in the testing data have healthy tissues adjacent to cancerous ones consistent with the challenge faced in lumpectomy surgeries. Results: The glycerol-treated tissues showed a decrease in the absorption coefficients compared with untreated tissues, especially as the period of treatment increased. Although the sensitivity metric of the classifier presented higher values in the untreated tissues compared with the treated ones, the specificity and accuracy metrics demonstrated higher values for the treated tissues compared with the untreated ones. Conclusions: The biocompatible glycerol solution is a potential optical clearance agent in THz imaging while keeping the histopathology imaging intact. The SAM technique provided a good classification of cancerous tissues despite the small amount of cancer in the training data (only 7%). The SAM exponential kernel and EMD presented classification accuracy of ∼80 % to 85% compared with linear and polynomial kernels that provided accuracy ranging from 70% to 80%. Overall, glycerol treatment provides a potential improvement in cancer classification in freshly excised breast tumors.

SPIE Journal Paper | 26 April 2021 Open Access

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

Nagma Vohra, Tanny Chavez, Joel Troncoso, Narasimhan Rajaram, Jingxian Wu, Patricia Coan, Todd Jackson, Keith Bailey, Magda El-Shenawee

JMI, Vol. 8, Issue 02, 023504, (April 2021) https://doi.org/10.1117/12.10.1117/1.JMI.8.2.023504

KEYWORDS: Tumors, Tissues, Terahertz radiation, Cancer, Pathology, Expectation maximization algorithms, Image segmentation, Tumor growth modeling, Breast cancer, Breast

Read Abstract +

DOWNLOAD PAPER

SPIE Journal Paper | 14 May 2019

Terahertz tomographic imaging of freshly excised human breast tissues

Tyler Bowman, Nagma Vohra, Keith Bailey, Magda El-Shenawee

JMI, Vol. 6, Issue 02, 023501, (May 2019) https://doi.org/10.1117/12.10.1117/1.JMI.6.2.023501

KEYWORDS: Tissues, Terahertz radiation, Cancer, Collagen, Imaging spectroscopy, Breast, Spectroscopy, Absorption, Refractive index, Reflection

Read Abstract +

SPIE Journal Paper | 14 February 2018 Open Access

Pulsed terahertz imaging of breast cancer in freshly excised murine tumors

Tyler Bowman, Tanny Chavez, Kamrul Khan, Jingxian Wu, Avishek Chakraborty, Narasimhan Rajaram, Keith Bailey, Magda El-Shenawee

JBO, Vol. 23, Issue 02, 026004, (February 2018) https://doi.org/10.1117/12.10.1117/1.JBO.23.2.026004

KEYWORDS: Tissues, Pathology, Cancer, Terahertz radiation, Tumors, Image classification, Breast cancer, Statistical modeling, Millimeter wave imaging, Statistical analysis

Read Abstract +

DOWNLOAD PAPER

SPIE Journal Paper | 24 January 2017 Open Access

Review of terahertz photoconductive antenna technology

Nathan Burford, Magda El-Shenawee

OE, Vol. 56, Issue 01, 010901, (January 2017) https://doi.org/10.1117/12.10.1117/1.OE.56.1.010901

KEYWORDS: Terahertz radiation, Principal component analysis, Antennas, Electrodes, Gallium arsenide, Terahertz technology, Plasmonics, Nanostructures, Signal to noise ratio, Sensors

Read Abstract +

DOWNLOAD PAPER

Proceedings Article | 18 March 2016 Presentation + Paper

Development of breast cancer tissue phantoms for terahertz imaging

Alec Walter, Tyler Bowman, Magda El-Shenawee

Proceedings Volume 9700, 970003 (2016) https://doi.org/10.1117/12.2211176

KEYWORDS: Terahertz radiation, Optical properties, Tissue optics, Tumors, Solids, Water, Cancer, Terahertz spectroscopy, Spectroscopy, Absorption, Refractive index, Breast cancer, Breast, Tissues

Read Abstract +

Proceedings Article | 18 March 2016 Presentation + Paper

Margin assessment of three-dimensional breast cancer phantoms using terahertz imaging

Tyler Bowman, Alec Walter, Magda El-Shenawee

Proceedings Volume 9700, 97000J (2016) https://doi.org/10.1117/12.2212671

KEYWORDS: Tumor growth modeling, Tumors, Reflection, Terahertz radiation, Optical phantoms, 3D image processing, Cancer, Millimeter wave imaging, Tissues, Breast cancer

Read Abstract +

Proceedings Article | 7 March 2016 Presentation + Paper

Adaptive enhancement and visualization techniques for 3D THz images of breast cancer tumors

Yuhao Wu, Tyler Bowman, John Gauch, Magda El-Shenawee

Proceedings Volume 9706, 970602 (2016) https://doi.org/10.1117/12.2209706

KEYWORDS: Terahertz radiation, Tissues, Visualization, Image enhancement, Image processing, Image segmentation, 3D image enhancement, 3D image processing, Cancer, Image visualization, Tumors, Breast cancer, Breast, Image filtering

Read Abstract +

Proceedings Article | 7 March 2016 Paper

Regional spectroscopy of paraffin-embedded breast cancer tissue using pulsed terahertz transmission imaging

Tyler Bowman, Magda El-Shenawee, Lucas Campbell

Proceedings Volume 9706, 97061W (2016) https://doi.org/10.1117/12.2212704

KEYWORDS: Imaging spectroscopy, Spectroscopy, Tissues, Breast cancer, Tissue optics, Terahertz spectroscopy, Cancer, Terahertz radiation, Absorption, Refractive index

Read Abstract +

Proceedings Article | 7 March 2016 Paper

Time of flight estimation for breast cancer margin thickness using embedded tumors

Tyler Bowman, Magda El-Shenawee, Lucas Campbell

Proceedings Volume 9706, 97061V (2016) https://doi.org/10.1117/12.2211167

KEYWORDS: Breast cancer, Millimeter wave imaging, Imaging systems, 3D image processing, Analytical research, Terahertz sources, Biological research, Reflection, Natural surfaces, Cancer, Tumors, Tissue optics, Terahertz radiation, Pathology

Read Abstract +

Proceedings Article | 25 February 2016 Paper

Simulation, fabrication, and measurement of a plasmonic-enhanced terahertz photoconductive antenna

Nathan Burford, Magda El-Shenawee

Proceedings Volume 9747, 974704 (2016) https://doi.org/10.1117/12.2217852

KEYWORDS: Terahertz radiation, Antennas, Gallium arsenide, Plasmonics, Principal component analysis, Thin films, Pyroelectric detectors, Thermography, Electrodes, Photons

Read Abstract +

Proceedings Article | 21 May 2004 Paper

Computational algorithm for reconstructing the profile of 2D rough surfaces

Magda El-Shenawee, Eric Miller

Proceedings Volume 5299, (2004) https://doi.org/10.1117/12.529306

KEYWORDS: Radar signal processing, Dielectric polarization, Optimization (mathematics), Electromagnetic radiation, General packet radio service, Detection and tracking algorithms, Dielectrics, Algorithm development, Receivers, Reconstruction algorithms

Read Abstract +

Proceedings Article | 11 September 2003 Paper

Covariance matrix for radar imaging of targets buried beneath two-dimensional rough surfaces

Magda El-Shenawee, Eric Miller

Proceedings Volume 5089, (2003) https://doi.org/10.1117/12.488497

KEYWORDS: Radar, Target detection, Scattering, Radar imaging, Backscatter, Electromagnetic scattering, Dielectrics, Polarimetry, 3D acquisition, Electromagnetic radiation

Read Abstract +

Proceedings Article | 11 September 2003 Paper

Scattering from dielectric targets buried beneath 2D randomly rough surfaces

Magda El-Shenawee, Carey Rappaport, Eric Miller

Proceedings Volume 5089, (2003) https://doi.org/10.1117/12.486752

KEYWORDS: Electrical engineering, Free space, Target detection, Dielectric polarization, Land mines, Monte Carlo methods, 3D acquisition, Polarimetry, Dielectrics, Scattering

Read Abstract +

Proceedings Article | 13 August 2002 Paper

Parametric investigation of ground roughness on the interference between AP-mine and clutter-object buried under two-dimensional random rough surfaces

Magda El-Shenawee, Carey Rappaport

Proceedings Volume 4742, (2002) https://doi.org/10.1117/12.479103

KEYWORDS: Scattering, Electromagnetic scattering, Magnetism, Electromagnetism, Land mines, Mining, Dielectrics, Multiple scattering, Target detection, 3D modeling

Read Abstract +

Proceedings Article | 13 August 2002 Paper

Hypothesis testing detection of mines buried under rough ground surfaces using 2D FDTD modeling

He Zhan, Carey Rappaport, Magda El-Shenawee, Eric Miller

Proceedings Volume 4742, (2002) https://doi.org/10.1117/12.479073

KEYWORDS: Monte Carlo methods, Receivers, Surface roughness, Reflection, Dielectrics, General packet radio service, Land mines, Target detection, Signal processing, Finite-difference time-domain method

Read Abstract +

In ground penetrating radar (GPR) antipersonnel mine sensing, in which the target is small, shallow and often of low dielectric contrast, detection is challenging. One of the difficulties is that it is hard to distinguish the target signal from the omnipresent random rough ground reflection clutter. In this work, a Monte Carlo computational simulation using 2-dimensional (2-D) transverse magnetic (TM) finite difference time domain (FDTD) with multiple rough surfaces is implemented to investigate single TNT target buries in dispersive soil. Based on the effects of the random rough surface on an impulse GPR signal and the knowledge of wave propagation differences in different media - air, soil, and TNT - a special background average process using physics based signal processing (PBSP) is performed to remove the ground clutter signal. This procedure first involves shifting and scaling multiple time signals from target-free random rough ground to establish the nominal (average) ground reflection pulse shape. Next, this nominal pulse shape is correlated in time with each trial signal, then shifted and scaled to match the ground surface clutter of that trial signal. Subtracting this shifted scaled clutter signal from the trial signal ideally leaves the target signal (with some additional multiple scattering between the target and ground surface). The PBSP algorithm reapplied in cases for which surface scattering occurs at multiple points. The statistical results of PBSP surface clutter removal indicate that the detection performance degrades with increasing surface roughness and decreasing burial depth. Hypothesis testing on the processed results proved to be successful in a detection and estimation point of view. This paper presents the detection performances in terms of Receiver Operating Characteristics (ROC) for various ground surface roughness and target burial depth cases. Also demonstrated is the performance improvements expected from multiple views: indicating that a multi-bistatic configuration appears to be superior to multistatic transmitter/receiver geometry with minimum combinations.

Proceedings Article | 13 August 2002 Paper

Scattering from multilayered random rough surfaces using the Steepest Descent Fast Multipole Method (SDFMM) and the multiple interaction model

Magda El-Shenawee

Proceedings Volume 4742, (2002) https://doi.org/10.1117/12.479075

KEYWORDS: Dielectrics, Near field, Optical spheres, Electromagnetic scattering, 3D modeling, Interfaces, Multilayers, Scattering, Magnetism, Multiple scattering

Read Abstract +

Proceedings Article | 18 October 2001 Paper

Statistics of electromagnetic near fields scattered from 3D AP mines buried under random rough surface calculated using the steepest descent fast multipole method (SDFMM)

Magda El-Shenawee, Carey Rappaport

Proceedings Volume 4394, (2001) https://doi.org/10.1117/12.445504

KEYWORDS: General packet radio service, Electromagnetism, Optical spheres, Monte Carlo methods, Gaussian beams, Scattering, Near field, Dielectrics, Interfaces, Mining

Read Abstract +

Proceedings Article | 22 August 2000 Paper

Quantifying the effects of different rough surface statistics for mine detection using the FDTD technique

Magda El-Shenawee, Carey Rappaport

Proceedings Volume 4038, (2000) https://doi.org/10.1117/12.396180

KEYWORDS: Composites, Monte Carlo methods, Finite-difference time-domain method, Land mines, Distortion, Surface roughness, Receivers, Transmitters, Correlation function, Fourier transforms

Read Abstract +

Proceedings Article | 30 October 1998 Paper

High-frequency approximations of the full wave solutions to single and double scatter cross sections for two-dimensional random rough surfaces

Ezekiel Bahar, Magda El-Shenawee

Proceedings Volume 3426, (1998) https://doi.org/10.1117/12.328459

KEYWORDS: Numerical analysis, Geometrical optics, Maxwell's equations, Electro optics, Receivers, Electromagnetism, Radar, Polarization, Scattering, Backscatter

Read Abstract +

The like and cross polarized single and double scattered fields are derived using a full wave approach. This approach is based on the complete expansion of the electromagnetic fields, the imposition of exact boundary conditions and the conversion of Maxwell's equations into generalized telegraphists equations for the scattered wave amplitudes. Thus, the zero order iterative solutions for the generalized telegraphists equations yield the primary electromagnetic (source) fields impressed upon the rough surface. The first and second order iterative solutions to the generalized telegropherts' equations yield the single and double scattered fields. This can be clearly demonstrated by taking the geometric optics limit of the full wave solutions. To obtain the corresponding like and cross polarized scatter cross sections, as in the case of scattering from one dimensional rough surfaces, it is necessary to account for contributions from the quasi parallel double scatter paths as well as the quasi antiparallel double scatter paths. However, for scattering from two dimensional rough surfaces, these paths are not restricted to the plane of incidence. The full wave solutions for the double scattered fields are expressed as six dimensional integrals, that account for the complete wave spectra of scattered fields and the coordinate variables at a pair of points on the rough surface. These expressions are used to obtain the multidimensional integrals for the like and cross polarized cross sections. To make these solutions tractable for computational purposes, a high frequency approximation of the full wave double scatter cross sections are expressed as four dimensional integrals involving scatter wave vector variables. These results can be evaluated in significantly less time than standard numerical solutions of the integral equations. Moreover, the physical interpretation of the results shed light on the impact, of different statistical parameters of the random rough surfaces, upon the backscatter enhancement.

Showing 5 of 20 publications

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Keywords/Phrases

Search In:

Publication Years