title: Multispectral imaging of tissue absorption and scattering using spatial frequency domain imaging and a computed-tomography imaging spectrometer.
abstract: We present an approach for rapidly and quantitatively mapping tissue absorption and scattering spectra in a wide-field, noncontact imaging geometry by combining multifrequency spatial frequency domain imaging (SFDI) with a computed-tomography imaging spectrometer (CTIS). SFDI overcomes the need to spatially scan a source, and is based on the projection and analysis of periodic structured illumination patterns. CTIS provides a throughput advantage by simultaneously diffracting multiple spectral images onto a single CCD chip to gather spectra at every pixel of the image, thus providing spatial and spectral information in a single snapshot. The spatial-spectral data set was acquired 30 times faster than with our wavelength-scanning liquid crystal tunable filter camera, even though it is not yet optimized for speed. Here we demonstrate that the combined SFDI-CTIS is capable of rapid, multispectral imaging of tissue absorption and scattering in a noncontact, nonscanning platform. The combined system was validated for 36 wavelengths between 650-1000 nm in tissue simulating phantoms over a range of tissue-like absorption and scattering properties. The average percent error for the range of absorption coefficients (μa) was less than 10% from 650-800 nm, and less than 20% from 800-1000 nm. The average percent error in reduced scattering coefficients (μs') was less than 5% from 650-700 nm and less than 3% from 700-1000 nm. The SFDI-CTIS platform was applied to a mouse model of brain injury in order to demonstrate the utility of this approach in characterizing spatially and spectrally varying tissue optical properties.
authors.affiliation: University of California, Irvine, Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road East, Irvine, California, 92612, USA.
authors.forename: Jessie R
authors.initials: JR
authors.lastname: Weber
authors.forename: David J
authors.initials: DJ
authors.lastname: Cuccia
authors.forename: William R
authors.initials: WR
authors.lastname: Johnson
authors.forename: Gregory H
authors.initials: GH
authors.lastname: Bearman
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Durkin
authors.forename: Mike
authors.initials: M
authors.lastname: Hsu
authors.forename: Alexander
authors.initials: A
authors.lastname: Lin
authors.forename: Devin K
authors.initials: DK
authors.lastname: Binder
authors.forename: Dan
authors.initials: D
authors.lastname: Wilson
authors.forename: Bruce J
authors.initials: BJ
authors.lastname: Tromberg
mesh_terms: D000818:Animals; D001923:Brain Chemistry; D001930:Brain Injuries / Q000175:diagnosis*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D051379:Mice; D009391:Nephelometry and Turbidimetry / Q000295:instrumentation*; D010100:Oxygen / Q000032:analysis*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013057:Spectrum Analysis / Q000295:instrumentation*; D018511:Systems Integration; D014057:Tomography, X-Ray Computed / Q000295:instrumentation*
chemical_list: D010100:Oxygen