title: In vivo near-infrared dual-axis confocal microendoscopy in the human lower gastrointestinal tract.
abstract: Near-infrared confocal microendoscopy is a promising technique for deep in vivo imaging of tissues and can generate high-resolution cross-sectional images at the micron-scale. We demonstrate the use of a dual-axis confocal (DAC) near-infrared fluorescence microendoscope with a 5.5-mm outer diameter for obtaining clinical images of human colorectal mucosa. High-speed two-dimensional en face scanning was achieved through a microelectromechanical systems (MEMS) scanner while a micromotor was used for adjusting the axial focus. In vivo images of human patients are collected at 5 frames/sec with a field of view of 362×212 μm(2) and a maximum imaging depth of 140 μm. During routine endoscopy, indocyanine green (ICG) was topically applied a nonspecific optical contrasting agent to regions of the human colon. The DAC microendoscope was then used to obtain microanatomic images of the mucosa by detecting near-infrared fluorescence from ICG. These results suggest that DAC microendoscopy may have utility for visualizing the anatomical and, perhaps, functional changes associated with colorectal pathology for the early detection of colorectal cancer.
authors.affiliation: Stanford University, James H. Clark Center for Biomedical Engineering & Sciences, Department of Pediatrics, Stanford, California 94305, USA. wibool@gmail.com
authors.forename: Wibool
authors.initials: W
authors.lastname: Piyawattanametha
authors.forename: Hyejun
authors.initials: H
authors.lastname: Ra
authors.forename: Zhen
authors.initials: Z
authors.lastname: Qiu
authors.forename: Shai
authors.initials: S
authors.lastname: Friedland
authors.forename: Jonathan T C
authors.initials: JT
authors.lastname: Liu
authors.forename: Kevin
authors.initials: K
authors.lastname: Loewke
authors.forename: Gordon S
authors.initials: GS
authors.lastname: Kino
authors.forename: Olav
authors.initials: O
authors.lastname: Solgaard
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Wang
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Mandella
authors.forename: Christopher H
authors.initials: CH
authors.lastname: Contag
mesh_terms: D020776:Endoscopes, Gastrointestinal; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation*; D007259:Infrared Rays; D007909:Lenses; D018613:Microscopy, Confocal / Q000295:instrumentation*; D008904:Miniaturization; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*