LCIを使いこなす—上部消化管

Detection and Diagnosis of Tumors in the Upper Gastrointestinal Tract Using Linked Color Imaging

要旨●LCI（linked color imaging）は白色光観察用の光に加え，青紫色の短波長を強く照射し，さらに色調拡張技術を用いて赤色領域の彩度差・色相差を拡張する画像強調技術である．白色光同様に明るさが維持されるため，非拡大ルーチン検査に使用できる．上皮性腫瘍部は表面微小血管の増生を反映し，白色光観察では淡い発赤を呈することが多い．LCIでは発赤がより増強され，食道癌は濃い桃色，胃癌は橙赤色に描出されることが多い．背景粘膜との色調差が大きくなるため，病変は検出されやすくなる一方で，LCIでは多彩な色調で観察される胃炎所見について若干の習熟が必要である．

　LCI（linked color imaging）is an image enhanced endoscopy that uses intense irradiation with bluish-violet short wavelengths adding to light for WLI（white light imaging）. It uses color tone expansion technology in the red region and is an enhancement technique that retains brightness. It is suitable for non-magnified routine endoscopic examinations as well as WLI. Superficial microvessels in epithelial tumors increase and are seen as pale red areas in WLI. LCI enhances the redness. Esophageal cancer is often observed as dark pink, whereas gastric cancer is orange-red. Epithelial tumors are visually easier to detect considering the color differences between the background mucosa and tumors widen. Therefore, endoscopists should be familiar with gastritis findings in LCI which are observed in various colors.