Fig. 1.

Schematic for generating tumor oxygenation maps and PA spectral parameters. The ROI segmented from the US images is applied to the co-registered PA images at 750 and 850 nm which are then used to generate a tumor sO₂ map. Oxygenation histograms of every slice within the tumor provide a quantitative distribution of sO₂ values from which the average mode is calculated. The ROI mask is also applied to the reference phantoms at both wavelengths. The frequency information of the PA phantoms is subtracted from the tumor RF spectra and the normalized power spectra are used to retrieve the spectral parameters. For the US normalized spectra, the US image and reference phantom is used to obtain the same parameters.