Time resolved imaging through a highly scattering medium

Transmission images through a highly scattering medium have been obtained using picosecond pulses of visible light. The imaging method involves recording and discriminating between the times-of-flight of photons that penetrate th medium and using a fraction of the light with the shortest travel times to construct an image. The technique is being developed as a possible alternative method of screening for breast cancer without using potentially harmful x-rays. One- and two-dimensional images are presented of objects whose optical thicknesses are comparable with those of the human breast at visible wavelengths.