Monday 22 October 2012

Optimizing multi-dimensional terahertz imaging analysis for colon cancer diagnosis


Expert Systems with Applications
Available online 16 October 2012

Leila H. Eadie
Centre for Computational Intelligence, De Montfort University, The Gateway, Leicester, UK; Centre for Rural Health, Aberdeen University, Centre for Health Science, Old Perth Road, Inverness, UK

Abstract
Terahertz reflection imaging (at frequencies ∼0.1–10 THz/1012Hz) is non-ionizing and has potential as a medical imaging technique; however, there is currently no consensus on the optimum imaging parameters to use and the procedure for data analysis. This may be holding back the progress of the technique. This article describes the use of various intelligent analysis methods to choose relevant imaging parameters and optimize the processing of terahertz data in the diagnosis of ex vivo colon cancer samples. Decision trees were used to find important parameters, and neural networks and support vector machines were used to classify the terahertz data as indicating normal or abnormal samples. This work reanalyzes the data described in Reid et al. (Physics in Medicine and Biology, 2011, 56, 4333–4353), and improves on their reported diagnostic accuracy, finding sensitivities of 90–100% and specificities of 86–90%. This optimization of the analysis of terahertz data allows certain recommendations to be suggested concerning terahertz reflection imaging of colon cancer samples.

for full paper see http://www.sciencedirect.com/science/article/pii/S0957417412011335



terahertz medical imaging system core
... One or more normal and diseased samples were taken from each patient. The samples were imaged using a stand-alone portable THz system, the TPIimaga1000 (TeraViewLtd, Cambridge, UK) in reflection mode. Full details of the system can be found in Wallace et al. (2004). ...





Sunday 21 October 2012

Efficiency of using correlation function for estimation of probability of substance detection on the base of THz spectral dynamics

Vyacheslav A. Trofimov ; Nikolay V. Peskov ; Dmitry A. Kirillov

Proc. SPIE 8496, Terahertz Emitters, Receivers, and Applications III, 84960T (October 15, 2012); doi:10.1117/12.927441Text Size: A A A
From Conference Volume 8496

Terahertz Emitters, Receivers, and Applications III
San Diego, California, USA | August 12, 2012

Abstract

One of the problems arising in Time-Domain THz spectroscopy for the problem of security is the developing the criteria for assessment of probability for the detection and identification of the explosive and drugs. We analyze the efficiency of using the correlation function and another functional (more exactly, spectral norm) for this aim. ........

For full abstract see http://proceedings.spiedigitallibrary.org/proceeding.aspx?articleid=1380697

gantry


... For Time Domain Spectroscopy measurement the TeraView TPS 3000 unit with two accessories designed for the reflection was used [19].  ...




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Wednesday 10 October 2012

Terahertz imaging on subcutaneous tissues and liver inflamed by liver cancer cells


Terahertz Science and Technology, ISSN 1941-7411 Vol. 5, No. 3, September 2012


C. H. Zhang 1, 4, G. F. Zhao 2, B. B. Jin 1*, Y. Y. Hou 2*, H. H. Jia 3, J. Chen 1 and P. H. Wu 1*
1 Research Institute of Superconductor Electronics (RISE), School of Electronic Science and Engineering, Nanjing
University, Nanjing 210093, China
2 Immunology and Reproductive Biology Lab, Medical School & State Key Laboratory of Pharmaceutical
Biotechnology, Nanjing University, Nanjing, 210093, China
3 Currently National University of Defense Technology, Changsha, 410008, China
4 Institute of Laser Engineering, Osaka University, 2-6 Yamadaoka, Suita, Osaka 565-0871, Japan
*1 Email: bbjin@nju.edu.cn, *2 yayihou@nju.edu.cn & *1 phwu@nju.edu.cn


Abstract: 
Terahertz (THz) imaging has a number of potential applications in medical imaging and diagnosis. Here,we demonstrate the THz images on the diseased and the corresponding normal tissues from 14 samples. The liver cancer cells are planted by subcutaneous injection into BALB/c which share high degree homology with human.  Subcutaneous tumors and nearby normal tissues as well as the inflamed livers and normal liver tissues are achieved after 7 days, 14 days and 21 days injection. Terahertz time-domain spectroscopy (TDS) is used to image these tissues.  We have found that at certain frequency range, most tumors and serious inflamed livers have lower absorption that normal tissues, which mean THz imaging could obviously distinguish the tumors and normal tissues, serious inflamed and normal livers, but could not obviously distinguish the grade of tumors and inflammation.

TPS Spectra 300


... into slices. The size of slice is about 26 mm×20 mm×1.5 mm. 3. Experimental procedure In this study, all measurements are completed with a transmitted TDS imaging system (TPI Image 1000, TeraView Ltd, UK). A mode-locked ...






Tuesday 9 October 2012

Terahertz and mid-infrared spectroscopy of benzene-1,2-diol


Journal of Molecular Spectroscopy

Available online 2 October 2012

ZP Zheng, WH Fan, H Yan, J Liu, WZ Yang, SL Zhu 

State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China

Abstract

The terahertz (8-128 cm-1) and mid-infrared spectra (400-2000 cm-1) of benzene-1,2-diol at room temperature were measured by using terahertz time-domain spectroscopy and Fourier transform infrared spectroscopy, respectively. Comparing the experimental terahertz and mid-infrared spectra with computed results by density functional theory, we find that all the terahertz spectral features come from inter-molecular vibrations, and the mid-infrared spectral features mainly originate from intra-molecular vibrations, although inter-molecular vibrations still make the contributions in some extent.
The terahertz (THz) and mid-infrared (MIR) spectra of benzene-1,2-diol in the solid state have been modeled by density functional theory (DFT). Calculations of the vibrational spectra based on the optimized geometries provided a good fit to the observed spectra, and a more reasonable spectral reproduction has been achieved than those in previous work. For THz spectrum, the simulation based on the varied unit cell dimension has clearly shown that THz spectral reproduction is affected by the temperature change of unit cell. For MIR spectrum, band assignments are reported in terms of potential-energy distribution (PED), which differ to those previously reported for benzene-1,2-diol in some respects.

Full-size image (27 K)


... Experimentally, THz spectrum (8-128 cm -1 ) of benzene-1,2-diol was measured by using TPS
spectra 3000 (TeraView Limited) with the spectral resolution of 1.2 cm -1 . MIR spectrum....


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