Patent ID: 8204579

Claim:
A device comprising: a radiation source configured to produce electromagnetic radiation for irradiating a turbid medium at an excitation wavelength; a plurality of fluorescent electromagnetic radiation detectors configured to detect fluorescent electromagnetic radiation emitted at a fluorescence wavelength by a contrast agent applied to the turbid medium and in response thereto to produce fluorescence intensity data; a plurality of transmission electromagnetic radiation detectors configured to detect transmission electromagnetic radiation transmitted through the turbid medium at the excitation wavelength and in response thereto to produce transmission intensity data; and a processor, wherein distances between the fluorescent electromagnetic radiation detectors and the radiation source vary so as to produce distance-dependent fluorescence intensity data, and distances between the transmission electromagnetic radiation detectors and the radiation source vary so as to produce distance-dependent transmission intensity data, wherein the processor is configured to calculate ratios between the distance-dependent fluorescence intensity data and the distance-dependent transmission intensity data at a plurality of the distances, and to determine an amount of self-absorption of radiation by the contrast agent from a behavior of the ratios as a function of the distances.