colitic cancer/dysplasiaの画像診断―特殊光内視鏡を中心に

Diagnosis of Colitis-associated Cancer or Dysplasia, Using NBI（Narrow Band Imaging）and AFI（Autofluorescence Imaging）

要旨　潰瘍性大腸炎におけるNBI, AFIを用いたcolitis-associated cancer or dysplasiaに対するサーベイランスについて，われわれの検討を述べた．NBIによるサーベイランスは，色素拡大内視鏡を用いたサーベイランスと同等の診断能を有し，かつ検査時間の短縮に有用であった．AFIは，背景粘膜の炎症を反映してマゼンタを呈するため，サーベイランスにおいて注意を要するが，多発する炎症性ポリープ群から，詳細に観察する必要のない病変を拾い上げるのに有用ではないかと思われた．flat dysplasiaに対する検討を含め，実臨床に有用な特殊光観察によるサーベイランス法の確立が重要である．

　The efficacy of surveillance colonoscopy, using NBI and AFI for patients with ulcerative colitis（UC）is described. NBI may indirectly provide pit pattern diagnosis for UC-associated cancer or dysplasia（CC/D）. The accuracy of CC/D detection was equal to surveillance colonoscopy using NBI（NBI-SC）or surveillance colonoscopy, employing conventional magnifying chromoendoscopy（CHR-SC）. The major difference was in the total time needed for surveillance for colonoscopy. NBI-SC may soon and easily be substituted for NBI observation and conventional observation. NBI-SC has efficacy similar to CHR-SC as convenient optical pancolonic chromoendoscopy, and is a very useful and time saving procedure for detection of CC/D in UC patients.

　Our preliminary study revealed the relationship of AFI observation and histological activities of UC. Colonic remission mucosa of patients with UC can be detected as magenta by AFI. We need also further examinations to verify the efficacy of surveillance colonoscopy by using AFI.