Figure 2.

Spectral unmixing of the MSOT data. A) The spectral unmixing algorithm found nine distinct spectral components that agree with features of endogenous chromophores (hemoglobin, lipids, water, melanin, collagen). B–D) Spectral contrast of a representative ulnar nerve, visualized by color coding three components per image. The spectral data inside the nerve is shown with adjusted contrast and slightly smoothed in the lower left of each panel. E) Mean and standard deviations of the normalized spectra of the structures that are highlighted with white arrows in (C–E)—the artery to the right of the nerve, the epidermis, the subcutaneous fat, the dermis, the muscle, and the ulnar nerve. To the right of the graphs, the corresponding mean unmixing coefficients are displayed. HbO2: oxygenated hemoglobin, HHb: deoxygenated hemoglobin.