title: Optical Microangiography: High-Definition Magnification Colonoscopy with Narrow Band Imaging (NBI) for Visualizing Mucosal Capillaries and Red Blood Cells in the Large Intestine.
abstract: OBJECTIVE
  Recent advances in zoom endoscopy have enabled the subepithelial capillary network (SECN) in different organs of the gastrointestinal tract to be visualized. Ex vivo studies have suggested that the SECN demonstrates a honeycomb-like structure in the large intestine, but this has not yet been visualized in vivo. The high clarity and resolution of narrow-band imaging (NBI) may allow visualization at the single red-blood-cell (RBC) level and more accurate visualization of the SECN. We investigated whether high-definition magnification colonoscopy with NBI is useful for visualizing capillaries and RBCs in the large intestine.
  
  
  METHODS
  Sixteen patients with bowel symptoms undergoing routine colonoscopy with normal findings in a tertiary referral academic gastroenterology and endoscopy unit were included in the study. Total colonoscopies were performed using a high-definition magnification colonoscope (CF-H260AZI, Olympus, Tokyo) and a prototype high-definition electronic endoscopy system capable of NBI. Each part of the large intestine (cecum, ascending, transverse, descending, and sigmoid colon, and rectum) was observed at the maximum magnification with white-light imaging (WLI) and NBI. The normal honeycomb-like SECN and RBC movement by high-definition magnification colonoscopy with either WLI or NBI was prospectively successfully visualized for each part of the large intestine.
  
  
  RESULTS
  In all subjects, high-definition magnification colonoscopy with NBI allowed the visualization of a honeycomb-like SECN together with RBC movement in each segment of the large intestine except for the rectum. In contrast, with WLI alone, neither this SECN structure nor RBC movement could be detected.
  
  
  CONCLUSIONS
  High-definition magnification colonoscopy with NBI could be a new optical method for facilitating noninvasive investigations of both the microvascular architecture and microcirculation without the need for contrast materials.
authors.affiliation: Wolfson Digestive Disease Centre, Queen's Medical Centre Campus, Nottingham University Hospitals NHS Trust, United Kingdom.
authors.forename: Kenshi
authors.initials: K
authors.lastname: Yao
authors.forename: George K
authors.initials: GK
authors.lastname: Anagnostopoulos
authors.forename: Aida U
authors.initials: AU
authors.lastname: Jawhari
authors.forename: Philip V
authors.initials: PV
authors.lastname: Kaye
authors.forename: Chris J
authors.initials: CJ
authors.lastname: Hawkey
authors.forename: Krish
authors.initials: K
authors.lastname: Ragunath