title: Single-channel prototype terahertz endoscopic system.
abstract: We demonstrate the design and development of an innovative single-channel terahertz (THz) prototype endoscopic imaging system based on flexible metal-coated THz waveguides and a polarization specific detection technique. The continuous-wave (CW) THz imaging system utilizes a single channel to transmit and collect the reflected intrinsic THz signal from the sample. Since the prototype system relies on a flexible waveguide assembly that is small enough in diameter, it can be readily integrated with a conventional optical endoscope. This study aims to show the feasibility of waveguide enabled THz imaging. We image various objects in transmission and reflection modes. We also image normal and cancerous colonic tissues in reflectance mode using a polarization specific imaging technique. The resulting cross-polarized THz reflectance images showed contrast between normal and cancerous colonic tissues at 584 GHz. The level of contrast observed using endoscopic imaging correlates well with contrast levels observed in ex vivo THz reflectance studies of colon cancer. This indicates that the single-channel flexible waveguide-based THz endoscope presented here represents a significant step forward in clinical endoscopic application of THz technology to aid in in vivo cancer screening.
authors.affiliation: University of Massachusetts Lowell, Department of Physics, Massachusetts 01854, United StatesbBiomedical Terahertz Technology Center, Lowell, Massachusetts 01854, United States.
authors.forename: Pallavi
authors.initials: P
authors.lastname: Doradla
authors.affiliation: University of Massachusetts Medical School, Division of Colon and Rectal Surgery, Worcester, Massachusetts 01605, United States.
authors.forename: Karim
authors.initials: K
authors.lastname: Alavi
authors.affiliation: University of Massachusetts Lowell, Department of Physics, Massachusetts 01854, United StatesbBiomedical Terahertz Technology Center, Lowell, Massachusetts 01854, United States.
authors.forename: Cecil
authors.initials: C
authors.lastname: Joseph
authors.affiliation: University of Massachusetts Lowell, Department of Physics, Massachusetts 01854, United StatesbBiomedical Terahertz Technology Center, Lowell, Massachusetts 01854, United States.
authors.forename: Robert
authors.initials: R
authors.lastname: Giles
mesh_terms: D003110:Colonic Neoplasms / Q000473:pathology*; D020685:Colonoscopes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007834:Lasers; D007909:Lenses; D010865:Pilot Projects; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D020349:Surface Plasmon Resonance / Q000295:instrumentation*; D055069:Terahertz Imaging / Q000295:instrumentation*