Mechanisms of ratio fluorescence imaging of diseased tissue

Jianan Y. Qu; Calum E. MacAulay; Stephen Lam; Branko Palcic

doi:10.1117/12.206806

12 April 1995 Mechanisms of ratio fluorescence imaging of diseased tissue

Jianan Y. Qu, Calum E. MacAulay, Stephen Lam, Branko Palcic

Proceedings Volume 2387, Advances in Laser and Light Spectroscopy to Diagnose Cancer and Other Diseases II; (1995) https://doi.org/10.1117/12.206806
Event: Photonics West '95, 1995, San Jose, CA, United States

Abstract

The in vivo laser induced fluorescence experiments have shown that the intrinsic LIF spectral shape of bronchial dysplasia and carcinoma in situ does not differ significantly from that of normal bronchial tissue. However, the intensity of LIF from diseased tissue is significantly reduced. Comparing the in vivo measurement results and the Monte Carlo modeling based on measured optical properties, we have hypothesized that the factors which cause the fluorescence reduction in diseased tissue may be (i) thicker abnormal epithelium, (ii) slightly higher blood content, and (iii) reduction in the density of the fluorescence source density of submucosa. Based on the above hypothesis, the Monte Carlo simulation code was modified to allow one to model spectrally distorted (when compared to the intrinsic fluorescence spectra) fluorescence collected by an imaging system. The fluorescence images excited by He-Cd laser (442 nm) at three typical wavelengths (500 nm, 577 nm and 630 nm) were analyzed by using Monte Carlo simulations. The results indicated that even if there is not significant difference in spectral shape of intrinsic fluorescence between normal and abnormal bronchial tissue, the ratio of red (630 nm) to green (500 nm) fluorescence image from the modeled normal site is significantly higher than that from modeled abnormal site. And abnormal tissue can be identified by the ratio imaging technique. The major factor causing the increased red/green ratio at abnormal tissue sites is the different tissue optics between normal and abnormal tissue. In the in vivo study, five bronchial carcinoma in situ sites and 17 moderate/sever dysplasia lesions were examined by a ratio fluorescence imaging system through a bronchoscope. The red/green ratios of carcinoma in situ sites and dysplasia sites were found to be 1.85 +/- 0.2 and 1.7 +/- 0.2 higher than that of normal sites. This was consistent with the simulation results.

Citation Download Citation

Jianan Y. Qu, Calum E. MacAulay, Stephen Lam, and Branko Palcic "Mechanisms of ratio fluorescence imaging of diseased tissue", Proc. SPIE 2387, Advances in Laser and Light Spectroscopy to Diagnose Cancer and Other Diseases II, (12 April 1995); https://doi.org/10.1117/12.206806

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available