螢光内視鏡検査における励起フィルターの改良について

抄録

The fluorescence endoscopy was first reported by Katu in 1975. We took regards that there was great correlation between local hemodynamics in the gastrointestinal mucosa and the time required until fluorescence appeared after the intravenous administration of 10% sodium fluorescein dye. The aim of this study was to observe hemodynamics around the ulcerative lesions more clearly by modifying the original method at the point of excitation of the dye. The FITC interference filter which was commonly used for excitation of the dye had another characteristics to transmit red light, 630nm of peak frequency, without exciting potential. This characteristics was necessary to keep vision until fluorescence appeared when we tried to pursue fluorescence endoscopy. But, because of this chischaracteristics, fluorescent light observed through the barrier filter was interfered with the red light. Con-sequently, fluorescent light was obscured and difficult to detect if it was feeble. On this conception, the red light must be suppressed as weak as possible to keep orientation endoscopically. We succeeded to satisfy this necessity by attaching BG 14 (an excitation filter, Olympus company limited) with the F1TC interference filter. In clinical cases, we could observed fluorescent light more clearly and recognize localization more sharply as nearly natural green color of fluorescence. From these results, we thought we could applicate this modified method in the clinical field.