ABSTRACT
This chapter discusses the fluorescence imaging in whole living organisms, or macroscopic fluorescence imaging. It introduces a general mathematical framework that allows direct comparison of spectral and lifetime multiplexing. The chapter argues that the asymptotic method offers significantly improved quantitation and localization performance over the direct time domain (TD) methods for multiplexing problems and that the matrix formulation provides a clear and rigorous explanation for the distinct performance between the methods. Considering the spectral inverse problem, it is first possible to show that there are two ways to perform spectral inversion, analogous to the direct TD and asymptotic TD for the TD problem. An interesting question is the spatial resolution capability of tomographic fluorescence imaging. Although no systematic studies have been reported to date characterizing the resolution of fluorescence tomography across various length scales, submillimeter resolution has been reported using continuous wave imaging in small animal-size phantoms.
