Open AccessApplying time-dependent data for fluorescence tomography
Author(s) -
Ralf B. Schulz,
Martin Schweiger,
Cosimo D’Andrea,
Gianluca Valentini,
Jessica Peter,
Rinaldo Cubeddu,
Simon Arridge,
Willi Semmler
Publication year - 2007
Publication title -
proceedings of spie, the international society for optical engineering/proceedings of spie
Language(s) - English
Resource type - Conference proceedings
SCImago Journal Rank - 0.815
H-Index - 60
eISSN - 1996-756X
pISSN - 0277-786X
DOI - 10.1117/12.728357
Subject(s) - contrast (vision) , computer science , iterative reconstruction , optics , physics , fluorescence , fluorescence lifetime imaging microscopy , photon , diffuse optical imaging , diffusion , data acquisition , scattering , tomographic reconstruction , inverse problem , signal (programming language) , frame rate , tomography , artificial intelligence , mathematics , thermodynamics , programming language , operating system , mathematical analysis
Can time-resolved, high-resolution data as acquired by an intensified gated CCD camera (ICCD) aid in the tomographic reconstruction of fluorescence concentration? Usually it is argued that fluorescence is a linear process and thus does not require non-linear, time-dependent reconstructions algorithms, unless absorption and scattering coefficients need to be determined as well. Furthermore, the acquisition of a number of time frames is usually prohibitive for fluorescence measurements, at least in small animals, due to the increased total measurement time. On the other hand, it is obvious that diffusion is less pronounced in images at early gates, due to selective imaging of photons of lower scatter order. This will be the case also for photons emitted by fluorescent sources. Early-gated imaging might increase the contrast in acquired images and could possibly improve fluorescence localization. Herein, we present early gated fluorescence images obtained from phantoms and compare them to continuously acquired data. Increased contrast between background and signal maximum can be observed in time-gated images as compared to continuous data. To make use of the properties exhibited by early gated frames, it is necessary to use a modified reconstruction algorithm. We propose a variant of the well-known Born approximation to the diffusion equation that allows to take into account single time frames. The system matrix for the time-dependent Born approach is more complex to calculate, however the complexity of the actual inverse problem (and the acquisition times) of single-frame reconstructions remains the same as compared to continuous mode