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Time-resolved
reflectance and transmittance spectroscopy and imaging for medical diagnostics
Taroni, Paola1
INFM-Dipartimento di Fisica and CEQSE-CNR, Politecnico di Milano1
Abstract-
Time-resolved reflectance and transmittance spectroscopy allows the
non-invasive measurement of both absorption and transport scattering
coefficients of highly diffusive media, such as biological tissues.
Based on this technique, we developed a fully automated system for the
complete optical characterization of tissues in vivo over a wide spectral
range (600-1000 nm). The interpretation of the absorption spectra yields
the concentrations of the main tissue constituents, and can monitor
their patho-physiological changes. On the other hand, the scattering
spectra depend on the average size and concentration of the scattering
structures, and provide information on tissue morphology. As an example
of application, the spectroscopy system allowed us to investigate how
the optical properties of the female breast change with the menstrual
cycle. In particular, such information is of use for the development
of optical mammography. To test the diagnostic potential of this novel
technique in a clinical study, we have recently realized a portable
system, which provides optical images of the compressed breast for tumor
detection, based on the acquisition of time-resolved transmittance data
combined with scanning over the region of interest. A second portable
system has been designed for oximetry and functional studies of the
brain activity. In this case, fast acquisition is performed, with multiple
sources/detectors capability, in order to allow monitoring of rapid
changes in blood volume and oxygen saturation over an extended area.
Keywords: optical
properties, tissue spectroscopy and imaging
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