Multispectral imaging of tissue absorption and scattering using spatial frequency domain imaging and a computed-tomography imaging spectrometer.

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.

Fluorescence-guided laser removal of chemically damaged cornea.

Purpose: To correlate the observed fluorescence spectrum with the depth of ablation during 193 nm argon-fluoride excimer laser ablation of chemically damaged corneas.

Setting: Laser facility, Cedars-Sinai Medical Center, Los Angeles, California, USA.

Methods: Three cadaver New Zealand white rabbit corneas were exposed to 1 N hydrogen chloride for 10 seconds.