Autofluorescence spectroscopy of normal and pathological tissues of the bladder

Autofluorescence spectra of normal and pathological mucosa of the bladder were measured in vivo in five patients using 410 nm excitation light and ex vivo in five samples, within 30 minutes after removal, using both 364 and 400 nm excitation lights. Inflammatory and angiodysplasia post-radiotherapy lesions, and papilloma were differentiated from normal mucosa by the low autofluorescence intensity and the shape of spectra. The autofluorescence intensity ratio, at a common emission peak (515 - 520 nm) induced by 410 nm and 1 mW excitation light, between normal mucosa and pathological tissues for each patient was variable. A minimum of 5 and a maximum of 22.5 were observed. The autofluorescence intensity for certain inflammatory post-radiotherapy lesions was null. Furthermore, due to high absorption of hemoglobin, spectra of angiodysplasia post-radiotherapy lesions were characterized by two peaks at about 555 and 600 nm. The measured autofluorescence spectra in samples caused by two excitation wavelengths (360 & 400 nm) and 1 mW light power showed similar structures to in vivo results. Though, a NADH peak appeared in variable intensities in spectra of both normal and pathological tissues at the excitation light of 364 nm. In certain lesions, this emission was highly attenuated.