内視鏡による早期胃癌のIIb進展範囲診断―AFI（autofluorescence imaging）の立場から

Autofluorescence Imaging in Diagnosis of Type IIb Early Gastric Cancers

要旨　画像強調法の内視鏡技術の発達により，AFIなどの新しい診断方法が進歩してきている．AFIでは励起光を照射した際に発生する消化管組織中の自家蛍光を専用のCCDで検出することにより，正常組織や腫瘍組織，炎症などを鑑別することが可能である．AFIによる胃癌の範囲診断は全体として色素内視鏡には劣るものの，平坦病変の補助診断法としての有効性が期待される．

　The invention of Equip-based image enhanced endoscopy, e.g. the autofluorescence imaging videoendoscopy system（AFI）, has developed greater diagnostic accuracy developed. Natural tissue fluorescence from endogenous fluorophores in the digestive tract is emitted by excitation light. This autofluorescence is detected by the exclusive endoscopic CCD. The image composed by autofluorescence makes it possible to distinguish tumor from normal tissue and inflammation. Because of the color difference in the AFI image, diagnostic accuracy by AFI for the extent of gastric cancer was better than that in conventional white light images but was not as good as that of chromoendoscopy. We must pay attention to diagnose of the extent of gastric cancer not only by AFI but by mutiple endoscopic modalities.