Development of a synchronous fluorescence imaging system and data analysis methods

Abstract

Although conventional autofluorescence spectroscopy, in which fluorescence emission spectra are recorded for fixed excitation wavelengths, has demonstrated good performance in tissue diagnosis, it suffers from prolonged data acquisition time and broad-band fluorescence features. Synchronous spectroscopy has been proposed to overcome the limitations of conventional fluorescence spectroscopy but has not been applied to imaging for tissue diagnosis in vivo. Our group has developed a synchronous fluorescence imaging system to combine the great diagnostic potential of synchronous spectroscopy and the large field of view of imaging for cancer diagnosis. This system has been tested in a mouse skin model to capture synchronous fluorescence images. A simple discriminant analysis method and a more complicated multi-variate statistical method have been developed to generate a single diagnostic image from a large number of raw fluorescence images. Moreover, it was demonstrated that the diagnostic image generated from synchronous data is comparable to that generated from full spectral data in classification accuracy.

Compact point-detection fluorescence spectroscopy system for quantifying intrinsic fluorescence redox ratio in brain cancer diagnostics

“…The statistical analysis method involves multiple steps using a leave-one-out scheme. 25 In the first step, one sample was kept for test and the rest of samples were used for training. The derived redox ratio data in the training set were used to train a discriminant classifier that performs quadratic discriminant analysis.…”

“…In the second data analysis, a multivariate statistical method and the leave-one-out scheme 25 were employed to evaluate the diagnostic value of the entire fluorescence spectra. Similar to the first data analysis, the analysis also involves multiple steps.…”

Analysis of ovarian tumor pathology by Fourier Transform Infrared Spectroscopy

“…Spectroscopic techniques such as fluorescence and nuclear magnetic resonance (NMR) have been employed to distinguish cancerous and non-cancerous states of a tissue [8]. Fluorescence spectroscopy can provide biochemical information about the state of a tissue, but suffers from broad band fluorescence features [9]. There are only a small number of endogenous fluorophores in cancerous tissue to provide fluorescent signals and hence give rise to undesirable broad spectral features [10].…”

Instrumentation in Diffuse Optical Imaging

“…With the continuously tunable filters, multi-fluorophore discrimination can be dramatically enhanced by spectral deconvolution [55]; and high-content fluorescent samples can be quickly and effectively analyzed using synchronous fluorescence, which scans the spectrum of interest with fixed excitation-emission wavelength distance [56]. …”