Device and method for multispectral optoacoustic imaging

A device for multispectral optoacoustic imaging of an object, the device comprising

• a) an irradiation unit configured to irradiate the object with electromagnetic radiation at two or more different irradiation wavelengths (λ), said electromagnetic radiation having a time-varying intensity,
• b) 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 (λ), and
• c) a processing unit configured
• to reconstruct images (P(r, λ)) of the object based on the detected acoustic waves generated in the object at each of the irradiation wavelengths (λ) and
• to determine a spatial distribution of at least one first concentration value (c′HbO2, c′HHb), which relates to a concentration of at least one electromagnetic radiation absorber (HbO2, HHb) in the object, wherein the determination of the spatial distribution of the at least one first concentration value (c′HbO2, c′HHb) is based on
• the reconstructed images (P(r, λ)) at the different irradiation wavelengths (λ),
• at least one wavelength-dependent extinction coefficient (ε1(λj), ε2(λj)) of the at least one electromagnetic radiation absorber (HbO2, HHb) in the object, and
• a linear combination of at least two model spectra (ΦM(λ), Φi(λ)), the model spectra (ΦM(λ), Φi(λ)) representing wavelength-dependent basis functions of a radiation fluence (Φ(r,λ)) or of a function (Φ′(r,λ)) of a radiation fluence (Φ(r,λ)), in particular a normalized radiation fluence (Φ(r,λ)/∥Φ(r)∥), in the object.