title: Toward whole-body optical imaging of rats using single-photon counting fluorescence tomography.
abstract: We used single-photon counting (SPC) detection for diffuse fluorescence tomography to image nanomolar (nM) concentrations of reporter dyes through a rat. Detailed phantom data are presented to show that every centimeter increase in tissue thickness leads to 1 order of magnitude decrease in the minimum fluorophore concentration detectable for a given detector sensitivity. Specifically, here, detection of Alexa Fluor 647 dyes is shown to be achievable for concentrations as low as 1 nM (<200 fM) through more than 5 cm in tissue phantoms, which indicates that this is feasible in larger rodent models. Because it is possible to detect sub-nM fluorescent inclusions with SPC technology in rats, it follows that it is possible to localize subpicomolar fluorophore concentrations in mice, putting the concentration sensitivity limits on the same order as nuclear medicine methods.
authors.affiliation: Thayer School of Engineering, Dartmouth College, 8000 Cummings Hall, Hanover, New Hampshire 03755, USA. Frederic.Leblond@dartmouth.edu
authors.forename: Frederic
authors.initials: F
authors.lastname: Leblond
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Tichauer
authors.forename: Robert W
authors.initials: RW
authors.lastname: Holt
authors.forename: Fadi
authors.initials: F
authors.lastname: El-Ghussein
authors.forename: Brian W
authors.initials: BW
authors.lastname: Pogue
mesh_terms: D000818:Animals; D004867:Equipment Design; D005453:Fluorescence; D005456:Fluorescent Dyes; D019047:Phantoms, Imaging; D017785:Photons; D051381:Rats; D012680:Sensitivity and Specificity; D014054:Tomography / Q000295:instrumentation / Q000379:methods; D051598:Whole Body Imaging
chemical_list: D005456:Fluorescent Dyes