title: Improved visibility of colorectal flat tumors using image-enhanced endoscopy.
abstract: Colonoscopy is considered the gold standard for detecting colorectal tumors; however, conventional colonoscopy can miss flat tumors. We aimed to determine whether visualization of colorectal flat lesions was improved by autofluorescence imaging and narrow-band imaging image analysis in conjunction with a new endoscopy system. Eight physicians compared autofluorescent, narrow-band, and chromoendoscopy images to 30 corresponding white-light images of flat tumors. Physicians rated tumor visibility from each image set as follows: +2 (improved), +1 (somewhat improved), 0 (equivalent to white light), -1 (somewhat decreased), and -2 (decreased). The eight scores for each image were totalled and evaluated. Interobserver agreement was also examined. Autofluorescent, narrow-band, and chromoendoscopy images showed improvements of 63.3% (19/30), 6.7% (2/30), and 73.3% (22/30), respectively, with no instances of decreased visibility. Autofluorescence scores were generally greater than narrow-band scores. Interobserver agreement was 0.65 for autofluorescence, 0.80 for narrow-band imaging, and 0.70 for chromoendoscopy. In conclusion, using a new endoscopy system in conjunction with autofluorescent imaging improved visibility of colorectal flat tumors, equivalent to the visibility achieved using chromoendoscopy.
authors.affiliation: Department of Endoscopy, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Shiro
authors.initials: S
authors.lastname: Oka
authors.forename: Naoto
authors.initials: N
authors.lastname: Tamai
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Ikematsu
authors.forename: Takuji
authors.initials: T
authors.lastname: Kawamura
authors.forename: Manabu
authors.initials: M
authors.lastname: Sawaya
authors.forename: Yoji
authors.initials: Y
authors.lastname: Takeuchi
authors.forename: Toshio
authors.initials: T
authors.lastname: Uraoka
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Moriyama
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kawano
authors.forename: Takahisa
authors.initials: T
authors.lastname: Matsuda
mesh_terms: D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000175:diagnosis*; D004396:Coloring Agents; D006801:Humans; D007089:Image Enhancement; D007203:Indigo Carmine; D062048:Narrow Band Imaging; D015588:Observer Variation; D012189:Retrospective Studies
chemical_list: D004396:Coloring Agents; D007203:Indigo Carmine
keywords: autofluorescence imaging; chromoendoscopy; colorectal flat tumor; image-enhanced endoscopy; narrow-band imaging