A method is disclosed for generating sinograms by sampling transducers acoustically coupled with a surface of a volume after a pulse of light, each transducer being associated with a channel in an optoacoustic imaging system, and processing at least two multi-channel sinograms, each corresponding to a different one of the at least two different predominant wavelengths, to create at least two processed sinograms. The processing step includes a step of sub-band acoustic compensation. Image reconstruction is performed based upon the processed sinograms to generate at least two optoacoustic images. Image post processing is performed on the optoacoustic images to generate post-processed images. A parametric map is generated based upon information contained in the post-processed images, and an ultrasound image is generated using the transducers. The parametric map and the ultrasound image are co-registered and a co-registered image is displayed.
