A photoluminescence technique is being investigated for detecting and monitoring nasopharyngeal carcinoma. This optical diagnostic technique could be non-invasive, continuous and economical. Fluorescence spectroscopy (FS) was performed on ten pieces of nasopharyngeal biopsy. The fluorescence spectra from malignant biopsies were found to differ from that of the normal biopsies. The intensity ratio of shorter to longer fluorescence spectra was computed and found to be able to differentiate malignant from normal tissues. In addition, FS technique may be used to determine the amount of connective tissue and diseases that are related to the synthesis of connective tissue....[ Read more ]

A photoluminescence technique is being investigated for detecting and monitoring nasopharyngeal carcinoma. This optical diagnostic technique could be non-invasive, continuous and economical. Fluorescence spectroscopy (FS) was performed on ten pieces of nasopharyngeal biopsy. The fluorescence spectra from malignant biopsies were found to differ from that of the normal biopsies. The intensity ratio of shorter to longer fluorescence spectra was computed and found to be able to differentiate malignant from normal tissues. In addition, FS technique may be used to determine the amount of connective tissue and diseases that are related to the synthesis of connective tissue.

Human tissue is a highly complex scattering medium that contains numerous chromophores. The presence of scatterers and the energy-transfer between the chromophores will change the observed fluorescence spectra. The fluorescence spectra of binary dye-mixtures in random media were studied experimentally. A dye-mixture of Coumarin 503 (donor) and Rhodamine B (acceptor) was made into a scattering medium by introducing various amount of latex beads. The fluorescence intensity of the acceptor was found to decrease as the volume fraction of latex beads was increased. A theoretical model was developed to analyze this observation. It suggests that the probability of energy-transfer may be represented by a multiplying factor which is independent of scattering parameters. This multiplying factor can be interpreted as the effective fluorescence yield of the binary dye-mixture. By measuring the bulk fluorescence intensity and the scattering and absorption parameters of a semi-infinite tissue, one can extract the effective fluorescence yield of the chromophore-mixture which could provide some useful biochemical information.