Multispectral optoacoustic (photoacoustic) tomography (MSOT) exploits high resolutions given by ultrasound detection
technology combined with deeply penetrating laser illumination in the near infrared. Traces of molecules with different
spectral absorption profiles, such as blood (oxy- and de-oxygenated) and biomarkers can be recovered using multiple
wavelengths excitation and a set of methods described in this work. Three unmixing methods are examined for their
performance in decomposing images into components in order to locate fluorescent contrast agents in deep tissue in
mice. Following earlier works we find Independent Component Analysis (ICA), which relies on the strong criterion of
statistical independence of components, as the most promising approach, being able to clearly identify concentrations
that other approaches fail to see. The results are verified by cryosectioning and fluorescence imaging.
A novel hybrid imaging system for simultaneous X-ray and Fluorescence Tomography
is presented, capitalizing on 360°-projection free-space fluorescence tomography. The system is
implemented within a commercial micro-CT scanner allowing reconstructions with a resolution of
95μm. Acquired data sets are intrinsically coregistered in the same coordinate system and can be
used to correctly localize reconstructed fluorescence distributions with morphological features.
More importantly, the micro-CT data, automatically segmented into different organ and tissue
segments can be used to guide the fluorescence reconstruction algorithm and reduce the ill coditioning
of the inverse problem. We showcase the use of the system and the improvements in
image quality for lesions in brain and lung.