BME Frontiers / 2020 / Article / Tab 2

Review Article

Terahertz Imaging and Spectroscopy in Cancer Diagnostics: A Technical Review

Table 2

Current ex vivo THz imaging studies.

AuthorsTHz systemImaging targetResults

Martin et al., 2016 [24]A continuous-wave THz imaging system working at 0.584 THz with circular polarizationFresh tumor and normal human skin tissue specimensContrast between cancerous and normal tissues was found with a resolution of 0.15 mm
Bowman et al., 2016 [25]A pulsed THz imaging and spectroscopy systemExcised paraffin-embedded breast tissue with breast invasive ductal carcinomaThe carcinoma areas exhibited lower transmission and higher reflection than normal areas as defined based on pathology
Yamaguchi et al., 2016 [26]A reflection THz time-domain spectroscopy systemFresh and paraffin-embedded tissues from a rat glioma modelA difference of 0.02 (0.8–1.5 THz) in the refractive index was found between glioma and normal area
Wahaia et al., 2016 [27]A continuous-wave THz imaging system working at 0.59 THzDehydrated human colon tissuesThe imaging resolution reached 500 μm
Grootendorst et al., 2017 [28]A handheld THz pulsed imaging systemFreshly excised breast cancer samplesThe identification accuracy of cancerous areas reached 75%
Bowman et al., 2018 [29]A pulsed THz imaging and spectroscopy systemFreshly excised murine xenograft breast cancer tumorsComparison with pathology results showed an accuracy above 80%
Cassar et al., 2018 [30]A pulsed THz imaging system with a reflection modeFreshly excised breast tissueThe spatial resolution reached 1 mm
Vohra et al., 2018 [31]A pulsed THz imaging system with a reflection modeFreshly excised and formalin/paraffin-fixed breast tumor tissues from a mouse modelCancerous areas exhibited the highest reflection and agreed with the pathology results
Yeo et al., 2019 [32]A pulsed THz imaging system with a reflection modeParaffin-embedded malignant tissues in human lung and small intestine tissuesThe adipose tissue area showed a lower refractive index and with a diffraction-limited spot size of ∼360 μm at 1 THz
Okada et al., 2019 [33]A scanning laser THz near-field reflection imaging systemParaffin-embedded human breast tissueThe spatial resolution reached 20 μm
Bowman et al., 2019 [34]A pulsed THz imaging and spectroscopy systemFreshly excised breast cancer tumorsThe cancerous areas exhibited higher absorption coefficients and refractive indexes than normal tissues, and the resolution reached 200 μm