12 April 1995 Mechanisms and limits of contrast in optical imaging of cancer
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The mechanisms of optical contrast in biological tissues and the limits of contrast are discussed. Some cancers develop as cellular masses which displace normal fibrous tissue or stroma, yielding a net drop in scattering properties. Some cancer may be more fibrous than normal tissues yielding a net increase in scattering. Cancers sometimes develop increased vascularity which yields a net increase in absorption. Another measure is fluorescence, either autofluorescence or dye-enhanced fluorescence. This paper considers the limits of resolution when optically characterizing a small spherical object within a turbid tissue. The ability to discriminate a small object with a strongly increased absorption vs a larger object with a slight increase in absorption is tested, using frequency-domain light transport with 3-GHz modulation of the light source. The results suggest that an object about 1/10 the size of the tissue within which it is embedded can be distinguished by a pair of measurements: the phase difference (Delta) P and the amplitude ratio A/A0.
© (1995) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Steven L. Jacques, "Mechanisms and limits of contrast in optical imaging of cancer", Proc. SPIE 2387, Advances in Laser and Light Spectroscopy to Diagnose Cancer and Other Diseases II, (12 April 1995); doi: 10.1117/12.206808; https://doi.org/10.1117/12.206808

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