Calibrated fluorescence imaging of tissue in vivo

A calibrated fluorescence imaging system utilizing a combination of fluorescence and cross-polarization imaging technology is described and applied to tissue examination in vivo. The results show that the inhomogeneity of fluorescence excitation and collection across the irregular surface of the examined tissue is calibrated to a great extent by taking the ratio of the raw fluorescence image to the cross-polarized reflection image. The effects of optical properties of tissue on the calibrated fluorescence signals are studies on simulated tissue phantoms systematically. Using the calibrated fluorescence imaging technology, we demonstrate that different tissue can be clearly separated endoscopically and in vivo based on the calibrated fluorescence signal.