| 摘要 |
<p>Optical diffusion waves are generated inside localized regions in highly scattering media such as human breast tissue by simultaneously using visible and near-infrared light and focusing ultrasound waves (6) in localized regions (8). The vibrating tissue medium scatters the impinging light to produce intensity-modulated diffusion waves (12). The diffusion waves (12) emanating from the insonified region have a frequency equal to the frequency (or a harmonic) of the ultrasound waves and detected at the boundary of the breast in order to acquire data for the density, absorption and scattering parameters in each localized region. A multiplicity of diffusion wave detectors (14) arranged at the boundary of the breast (4) detect scattered diffusion waves (12) at a multiplicity of locations. Each diffusion wave detector (14) comprises a photodetector (20) whose output signals are fed to a detector (22) which detects the amplitudes and phase of the diffusion waves (12). The amplitude and phase signal components of the diffusion waves (12) are supplied to a processor (24) which computes pixel values for display on a monitor (26). <IMAGE> <IMAGE></p> |
