Table 3.
Current THz breast imaging studies.
| Year | Frequency | THz System | Target | Results |
|---|---|---|---|---|
| Berry et al., 2003 [66] | 0.5–2.5 THz | TPI system | Various human tissues | Observed significant differences between broadband refractive indices of several tissues |
| Wallace et al., 2004 [31] | 0.1–3.0 THz | TPI scanner (Teraview Ltd., Cambridge, UK) |
BCC and healthy tissue | Could identify the extent of BCC in vivo and delineate tumor margins |
| Fitzgerald et al., 2006 [32] | 0.1–3.0 THz | TPI scanner (Teraview Ltd., Cambridge, UK) |
Freshly excised human breast tissues | Could depict invasive breast carcinoma and ductal carcinoma |
| Ashworth et al., 2009 [33] | 0.15–2.0 THz | A portable THz pulsed transmission spectrometer | Freshly excised human breast specimens | THz pulsed spectroscopy and TPI could distinguish healthy adipose breast tissue, healthy fibrous breast tissue, and breast cancer |
| Chen et al., 2011 [67] | 320 GHz | CW THz near-field microscopy transmission imaging | Frozen sliced breast tumors | Breast tumor could be distinguished from normal tissue without H&E staining with a resolution of 240 μm |
| Chen et al., 2011 [68] | 108 GHz | Fiber-scanning transmission THz imaging | Subcutaneous xenograft mouse | Detection limit for tumor size reached 0.05 mm3 |
| Joseph et al., 2011 [69] | 1.39 and 1.63 THz | CW THz transmission imaging | BCC | Observed good contrast between cancer and normal tissues with a spatial resolution of 390 μm at 1.4 THz and 490 μm at 1.6 THz |
| Peter et al., 2013 [70] | 1.89 THz | CW THz imaging mode | Human breast cancer tissue | Observed absolute refractive index values of samples |
| Bowman et al., 2015 [71] | 0.1–4.0 THz | TPS Spectra 3000 model | Paraffin-made breast phantoms | Could detect heterogeneous sample with a thickness of 10 μm |
| Bowman et al., 2016 [34] | 0.1–4.0 THz | TPS Spectra 3000 system | Excised breast carcinomas | Provided higher resolution and more apparent margins between cancerous and fibro, cancerous and fat, fibro and fat |
| Bowman et. al., 2017 [35] | 0.1–4.0 THz | TPS Spectra 3000 system | IDC and lobular carcinoma embedded in paraffin blocks | Tumor detection is accurate to depths over 1 mm. |
| Bowman et al., 2018 [72] | 0.5–1.0 THz | THz reflection mode | Freshly excised breast tumors | Achieved good agreement between THz and pathology images |
| Grootendorst et al., 2017 [37] | 0.1–1.8 THz | TPI handheld probe system (Teraview Ltd., Cambridge, UK) | Freshly excised breast cancer samples | Could discriminate breast cancer from benign tissue with an encouraging degree of accuracy |
| Chernomyred et al., 2018 [73] | 10.6 THz | CW THz SI microscopy reflectivity imaging system | Human breast specimen | Observed a fragment of the stroma of breast ex vivo |
| Cassar et al., 2018 [36] | 300–600 GHz | TPI and spectroscopy | Freshly excised murine xenograft breast cancer tumors | Cancerous identification accuracy of 80% |
| Bao et al., 2018 [74] | 0.06–4.0 THz | TeraPulse 4000 system (Teraview Ltd., Cambridge, UK) | Freshly excised breast tissue | Spatial resolution reached 1 mm |
| Vohra et al., 2018 [75] | 0.1–4.0 THz | TPI system with a reflection mode (Teraview Ltd., Cambridge, UK) |
Freshly excised and formalin/paraffin-fixed breast tumor tissues from a mouse model | Cancerous areas exhibited the highest reflection and agreed with the pathology results |
| Okada et al., 2019 [76] | ~~ | A scanning laser THz near-field reflection imaging system | Paraffin-embedded human breast | Spatial resolution reached 20 μm |
| Bowman et al., 2019 [77] | 0.5–1.0 THz | TPS Spectra 3000 pulsed THz imaging and spectroscopy system (Teraview Ltd., Cambridge, UK) | Freshly excised breast cancer tumors | Cancerous areas exhibited higher absorption coefficients and refractive indexes than normal tissues, and the resolution reached 200 μm |