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Colorectal
PWE-079 Characterisation colonic polyps using fice without optical magnification: a new classification system (N.A.C.)
  1. G Longcroft-Wheaton,
  2. P Bhandari
  1. Department of Gastroenterology, Portsmouth Hospitals NHS Trust, Portsmouth, UK

Abstract

Introduction FICE is a novel method of electronic imaging on fujinon endoscopes which enhances surface and vascular patterns. It can be used to predict histology of colonic polyps. However, there are no validated classification systems for using the technique without magnification. This study aims to validate a novel tool for this purpose.

Methods The optimum FICE setting was determined in a picture study. Digital photographs were taken of polyps with white light and all 10 FICE settings at 1026×770 resolution. They were reviewed by two endoscopists who scored each image for clarity of the mucosal and vascular patterns on a 3 point scale (0=poor, 3=excellent). A second library was examined to determine the criteria associated with hyperplastic polyps, adenomas and cancer. In each case the true histology was known. A prospective study was then performed to test the identified characteristics in vivo. Finally the criteria were used in a prospective study of polyps<10 mm in size within a screening population.

Results To determine the optimum FICE setting images of 30 polyps were examined. The Mean Score for the sum of all categories was 232 (SD=12) for assessor 1 and 242 (SD=29) for assessor 2. Setting 4 was superior, with a score 2 SDs above the mean for each assessor (256 and 322). There was no significant difference in scores for the other settings. To determine the N.A.C. criteria images of 67 polyps were examined. Vascularity with white light and FICE, and vascular and surface patterns with FICE were found to be predictive of the true histology. See Abstract PWE-079 table 1. These characteristics were assessed in vivo in 112 polyps<10 mm in size. The results were similar to those obtained in the picture study. The criteria were used as an in vivo diagnostic tool on 299 Polyps <10 mm. An accuracy of 87%, Sensitivity of 90%, and specificity of 81% was achieved.

Abstract PWE-079 Table 1

Conclusion This study demonstrates the optimum FICE setting and structural elements of polyps which can be exploited in making an in vivo diagnosis using FICE without magnification, and that they can be applied in a screening population of polyps <10 mm in size.

Competing interests None declared.

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