Fig. 1.

The typical redox images and the corresponding histograms of a normal tissue biopsy (image plane $\text{depth}=600\mu \mathrm{m}$) and a tumor tissue biopsy (image plane $\text{depth}=300\mu \mathrm{m}$) of the same patient (image matrix $128\times 128$, spatial resolution $100\mu \mathrm{m}$). The Fp or NADH images show the nominal concentrations in $\mu \mathrm{M}$, the Fp redox ratio ranges between 0 and 1. The $x$-axes of the corresponding histograms represent the concentrations or redox ratios. The $y$-axes of the histograms represent the number of pixels in the image plane having a specific value of concentration or the redox ratio. The round spots in the images are corresponding FAD or NADH reference standards.