Terahertz Imaging and Spectroscopy in Cancer Diagnostics: A Technical Review

Abstract

Terahertz (THz) waves are electromagnetic waves with frequency in the range from 0.1 to 10 THz. THz waves have great potential in the biomedical field, especially in cancer diagnosis, because they exhibit low ionization energy and can be used to discern most biomolecules based on their spectral fingerprints. In this paper, we review the recent progress in two applications of THz waves in cancer diagnosis: imaging and spectroscopy. THz imaging is expected to help researchers and doctors attain a direct intuitive understanding of a cancerous area. THz spectroscopy is an efficient tool for component analysis of tissue samples to identify cancer biomarkers. Additionally, the advantages and disadvantages of the developed technologies for cancer diagnosis are discussed. Furthermore, auxiliary techniques that have been used to enhance the spectral signal-to-noise ratio (SNR) are also reviewed.

Three-step one-way model in terahertz biomedical detection

“…Terahertz (THz) waves (0.1-10 THz) lie between the millimetre wave and infrared band, which is of significant importance to the biological sciences due to providing information complementary to traditional spectroscopic measurements of low-frequency bond vibrations, hydrogen bond stretching, and bond torsions in liquids and gases [12]. Therefore, the collective behaviour (vibration and rotation) characteristics of biomolecules make THz spectroscopy a promising sensing modality for clinical diagnosis [13].…”

Terahertz Imaging for Breast Cancer Detection

“…Based on these unique features, THz radiation has potential applications in biology [ 14 ], security [ 15 ], data communication [ 16 ], biomedical imaging [ 17 , 18 ], and food and agriculture [ 19 ]. Over the past two decades, THz imaging and spectroscopy have been investigated for biomedical applications [ 20 , 21 ], including diagnosis of liver cirrhosis [ 22 ], burn wounds [ 23 ], breast cancer [ 24 ], colon tumor [ 25 ], brain tumor [ 26 ], skin cancer [ 27 ], and other diseases [ 28 , 29 , 30 ].…”

The Conjugate Gradient Least Square Algorithm in Terahertz Tomography

“…Terahertz technologies offer a wide range of applications due to their ability to penetrate dielectric materials and to measure contactless without the need for radiation protection measures [1][2][3][4]. With regard to industrial applications, the field of nondestructive testing and thereby the determination of layer thicknesses [5,6] and imaging techniques for defect detection [7] are of particular relevance [8].…”