Near-infrared fluorescence contrast-enhanced imaging with area illumination and area detection: the forward imaging problem.
Fluorescence frequency-domain photon migration measurements were acquired from tissue phantoms, each containing a fluorescent target, by means of area illumination and area detection on the same surface and for the first time, to our knowledge, compared with predictions computed with a numerical solution to the coupled photon diffusion equations. We accomplished area illumination and area detection using a planar, intensity-modulated excitation light source and a gain-modulated intensified charge-coupled device camera, respectively. A 1-ml vessel containing 1-microm solution of Indocyanine Green in 1% Liposyn was immersed 1 cm deep in each 512-ml tissue phantom. For most tissue phantoms, the background surrounding the 1-ml target was composed of Liposyn solution containing Indocyanine Green or 3,3'-Diethylthiatricarbocyanine Iodide such that the target-to-background ratio of fluorescence yield was > or = 10:1. Measurements of fluorescence modulation amplitude and phase were predicted with a mean error ranging from 10.1% to 13.6% and 0.56 degrees to 1.72 degrees, respectively. These numbers are similar to those obtained by use of single-pixel frequency-domain photon migration techniques and validate the potential use of area illumination and area detection for biomedical imaging of tissues. Results also demonstrate that target-to-background ratios of fluorescence yield and fluorescence lifetime significantly affect target detectability.
Thompson
Alan B
AB
Photon Migration Laboratories, Texas A&M University, 3573 TAMU, College Station, Texas 77843-3573, USA.
Hawrysz
Daniel J
DJ
Sevick-Muraca
Eva M
EM
D003287:Contrast Media / Q000032:analysis* / Q000737:chemistry*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000295:instrumentation / Q000379:methods*; D008954:Models, Biological; D019047:Phantoms, Imaging; D011786:Quality Control; D012542:Scattering, Radiation; D019265:Spectroscopy, Near-Infrared / Q000295:instrumentation / Q000379:methods*
D003287:Contrast Media