Usefulness of linked color imaging in endoscopic diagnosis of SSA/P: A novel image enhancment technique.

AIM: Detection of SSA/P with conventional colonoscopy is relatively difficult because its appearance is flat and isochronous. Therefore, we investigated the usefulness of linked color imaging(LCI), a new optical image enhancement technique in laser endoscopy, in detecting SSA/P by comparing with other observation methods. METHODS: 1) fifty lesions in 37 patients were diagnosed as SSA/P histologically. Endoscopic images using white light(WL), LCI, blue laser imaging(BLI) and BLI-bright were digitally stored. Medical doctors including advisor, expert and non-expert interpreted still images. Detection rate of SSA/P in each mode was assessed. Detectability was evaluated: 1,not detectable; 2,barely detectable; 3,passably detectable; 4,easily detectable. 2) Color contrast between SSA/P and background mucosa was evaluated by calculating a color difference (δE). RESULTS: 1)Detection rate with LCI was the highest among the 4 modes in any of the medical adviser, expert and non-expert (LCI/WL/BLI/BLI-bright:100%/88%/70%/92%, 100%/92%/76%/88%, 96%/74%/64%/86%). The mean detectability score with LCI (3.15±0.77) was significantly higher than those with WL (2.39±0.78), BLI (2.33±1.11) and BLI-bright (2.61±0.92). 2)Color differences between SSA/P and background mucosa in WL, BLI, BLI-bright, and LCI were 13.2±6.7, 14.5±8.7, 12.8±6.2 and 19.6±5.3 respectively. There was a significant difference between LCI and WL, BLI or BLI-bright mode. CONCLUSION: LCI mode is superior to WL, BLI and BLI-bright mode in diagnosing SSA/P with significantly higher detection rate and color difference.