Pilot study of freshly excised breast tissue response in the 300 – 600 GHz range

Abstract

The failure to accurately define tumor margins during breast conserving surgery (BCS) results in a 20% re-excision rate. The present paper reports the investigation to evaluate the potential of terahertz imaging for breast tissue recognition within the under-explored 300 - 600 GHz range. Such a frequency window matches new BiCMOS technology capabilities and thus opens up the opportunity for near-field terahertz imaging using these devices. To assess the efficacy of this frequency band, data from 16 freshly excised breast tissue samples were collected and analyzed directly after excision. Complex refractive indices have been extracted over the as-mentioned frequency band, and amplitude frequency images show some contrast between tissue types. Principal component analysis (PCA) has also been applied to the data in an attempt to automate tissue classification. Our observations suggest that the dielectric response could potentially provide contrast for breast tissue recognition within the 300 - 600 GHz range. These results open the way for silicon-based terahertz subwavelength near field imager design, efficient up to 600 GHz to address ex vivo life-science applications.

Terahertz Imaging and Sensing Applications With Silicon-Based Technologies

“…The spatial resolution THz far-field imaging is fundamentally restricted by Abbe's diffraction limit, which is in the mm-range at THz frequencies. This can be far too low for many promising THz applications, e.g., semiconductor process quality control [131] and in situ assessment of malignant tissue margins during segmental mastectomy breast cancer surgeries [10]. In the last decades, there has thus been a significant interest in THz near fields which can interact with micro-and nanoscale phenomenon.…”

“…Markets and applications are projected to be fairly diverse for the terrestrial use of THz waves [6]. The uses span from potential large-volume applications, such as high-speed wireless communications [7] and radar gesture control [8] to small-volume niches in security inspection [9] and medical diagnosis [10]. This requires a diverse range of technology solutions, as an allin-one technology platform that offers high performance, low cost, and compactness at the same time does not exist yet.…”

Co-registered combined OCT and THz imaging to extract depth and refractive index of a tissue-equivalent test object

“…The image property used for each pixel in the OCT image was the maximum of the log intensity of the signal returned from the embedded objects. In a combined system, we would envisage THz imaging with normal incidence [36] or very near normal incidence [37] similar to the OCT set up. However, for this study, the THz imaging system used had a 30°angle of incidence and a larger scanning range of 20 mm, compared to 5 mm for the OCT system.…”

A Versatile Illumination System for Real-Time Terahertz Imaging

“…For more than a decade, terahertz imaging has demonstrated its ability to detect, localize or identify compounds inside optically opaque materials since some dielectric materials, like polymers or ceramics, have relatively low absorption coefficients in this part of the electromagnetic spectrum. Compared to other techniques, like ultrasounds or X-ray imaging, terahertz imaging represents a contact-free and harmless solution, suitable for many different potential non-destructive testing (NDT) applications such as maintenance or manufacturing industry of composite material [ 1 , 2 ], food quality inspection [ 3 , 4 ], art conservation and authentification [ 5 , 6 ] or for biomedical sciences [ 7 , 8 ]. Terahertz imaging can also be used as an efficient and alternative tool for metrology, allowing length extraction or surface and volume inspection [ 9 ].…”