Fluorescence Lifetime Imaging for Breast Cancer Detection and Diagnosis

Abstract

Abstract : The development of non-invasive, biomedical optical imaging from frequency-domain photon migration (FDPM) measurements of near-infrared (NIR) light propagation depends upon (i) the measurements of optical signals on the boundary of tissues and (ii) the numerical techniques enabling the reconstruction of interior optical properties from such measurements. From the mapping of interior optical properties, it is envisioned that diseased tissues can be identified and diagnosed based upon the differences in absorption and scattering properties. Briefly, FDPM consists of launching intensity-modulated light at the air-tissue interface and detecting the phase-delay and amplitude attenuation at another point distant from the incident point source. In the Purdue Photon Migration Laboratory (PPML), we have developed rapid multi-pixel methods for acquiring large data sets of phase-delay and amplitude attenuation across a tissue surface for use in an inversion algorithm in order to perform image reconstruction. In addition, since we have found that the endogenous contrast offered by absorption and scattering may be insufficient for biomedical imaging, we have invented a method for inducing contrast using fluorescent contrast agents. Algorithm development for biomedical fluorescence lifetime imaging was conducted under USAMRMC support. Using fluorescent agents, we have shown that the inverse problem may be better posed and that biodiagnostic information can be obtained from assessing the fluorescent decay kinetics within the tissue.