CW Fluorescence imaging of tissue-like media in reflectance geometry

N. CARBONE; D. I. IRIARTE; J. A. POMARICO; DIRK GROSENICK; RAINER MACDONALD

Munich

Congreso; European Conference on Biomedical Optics (ECBO 2015); 2015

SPIE

Tissue imaging using radiation in theinfrared region (NIR) has gained interest in the last years. Light interactswith biological tissues by events of absorption and scattering. In the NIRregion, scattering strongly dominates over absorption, and because of this,tissue behaves as a turbid medium which can be characterized by two basic opticalparameters, namely absorption (μa) and scattering coefficient (μs ).  Thisbehaviour imposes severe restrictions in recovering structural information;however it has also a number of advantages that makes imaging through NIRradiation an excellent technique as a complement of traditional modalities.Among them, different kinds of tissues and or lesions can be distinguished bytheir different values of the optical parameters. Besides, the radiation inthis spectral zone is completely harmless allowing its frequent utilization forcontinuous monitoring. This imaging techinque can be improved by the use offluorescent markers like indocyanine green (ICG). Different studies show thatthe pharmacokinetics of ICG is different in healthy tissues and in malignantlesions, allowing the observation of lesions by temporal discrimination offluorescence.  We present experimental results and simulations of CWimaging of turbid media phantoms with inclusions emulating lesions. Both, bulkand inclusion, contain realistic concentrations of absorber and ICG. The aim isto localize the inclusion by analysis of both, absorption and fluorescence data.