Feature extraction from light-scatter patterns of Listeria colonies for identification and classification

Abstract

We demonstrate fluorescence-enhanced optical imaging of single and multiple fluorescent targets within a large (∼1081 cm 3 ) phantom using frequency-domain photon migration measurements of fluorescence collected at individual points in response to illumination of excitation light at individual points on the boundary. The tissue phantom was filled with a 1% lipid solution with and without 0.01 μM Indocyanine Green (ICG) and targets consisted of vials filled with the 1% lipid containing 1-2.5 μM ICG. Measurements were acquired using a modulated intensified CCD imaging system under different experimental conditions. For 3-D image reconstruction, the gradient-based penalty modified barrier function (PMBF) method with simple bounds constrained truncated Newton with trust region method (CONTN) was used. Targets of 0.5, 0.6, and 1.0 cm 3 at depths of 1.4-2.8 cm from the phantom surface were tomographically reconstructed. This work demonstrates the practicality of fluorescence-enhanced tomography in clinically relevant volumes. © 2006 Society of Photo-Optical Instrumentation Engineers.