A device and an according method for multispectral optoacoustic imaging of an object is provided comprising: an irradiation unit configured to irradiate the object with electromagnetic radiation at two or more different irradiation wavelengths the electromagnetic radiation having a time-varying intensity; a detection unit configured to detect acoustic waves generated in the object upon irradiating the object with the electromagnetic radiation at the different irradiation wavelengths; and a processing unit configured to reconstruct images of the object based on the detected acoustic waves generated in the object at each of the irradiation wavelengths and to determine a spatial distribution of at least one first concentration value, which relates to a concentration of at least one electromagnetic radiation absorber in the object.