title: Fluorescein-enhanced autofluorescence imaging for accurate differentiation of neoplastic from non-neoplastic colorectal polyps: a feasibility study.
abstract: BACKGROUND
  Autofluorescence imaging (AFI) is sensitive but not specific for differentiating neoplastic from non-neoplastic colorectal polyps. We aimed to determine the sensitivity and specificity of fluorescein-enhanced AFI (FAFI) in differentiating neoplastic from non-neoplastic colorectal polyps.
  
  
  METHODS
  All patients with colorectal polyps detected during AFI colonoscopy received intravenous fluorescein followed by AFI (FAFI). The video sequences were recorded and divided into a learning group and a test group. AFI and FAFI criteria for neoplastic and non-neoplastic lesions were determined after viewing videos in the learning group unblinded to histology. Videos in the test group were viewed blinded to histology, and diagnoses of neoplastic versus non-neoplastic were made for AFI and FAFI using the predetermined criteria. Still frames were objectively measured for red:green ratio (AFI) and green contrast (FAFI).
  
  
  RESULTS
  Eight videos (four neoplastic, four non-neoplastic) were used for the learning group. Criteria for neoplasia when using FAFI were determined as the presence of a patchy or granular pattern which appeared more fluorescent green compared with the background. For AFI, purple or pink represented neoplasia; green represented non-neoplasia. In the test group (13 neoplastic, 12 non-neoplastic), for differentiating between neoplasia and non-neoplasia, subjective analysis of video sequences yielded a sensitivity of 100 % for AFI and 100 % for FAFI ( P = 1.000), and a specificity of 16.7 % for AFI and 91.7 % for FAFI ( P = 0.004). Using objective color analysis, the area under the receiver operating characteristics curve was 0.647 for AFI using the red:green ratio to distinguish between neoplasia and non-neoplasia, and 0.994 for FAFI using green contrast.
  
  
  CONCLUSIONS
  FAFI accurately differentiated between neoplastic and non-neoplastic colorectal polyps.
authors.affiliation: Department of Medicine II, Klinikum rechts der Isar, Technical University of Munich, Ismaningerstrasse 22, Munich, Germany.
authors.forename: L G
authors.initials: LG
authors.lastname: Lim
authors.forename: M
authors.initials: M
authors.lastname: Bajbouj
authors.forename: S
authors.initials: S
authors.lastname: von Delius
authors.forename: A
authors.initials: A
authors.lastname: Meining
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000175:diagnosis*; D003937:Diagnosis, Differential; D003952:Diagnostic Imaging / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D019793:Fluorescein; D005453:Fluorescence; D005456:Fluorescent Dyes; D006801:Humans; D007417:Intestinal Polyps / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence; D014741:Video Recording
chemical_list: D005456:Fluorescent Dyes; D019793:Fluorescein