How is near-infrared light used to image tissues in the human body?
Near-infrared light is found between the visible and microwave portions of the electromagnetic spectrum. For instance, when a stove coil is turned on, it will begin to radiate near-IR light just before the coils start to glow red. We can’t see near-IR light. Image enhancement techniques are used to amplify the near-infrared light that we can’t see with out eyes so that we can observe the image. Light travels at different speeds through different materials such as tissue. Near-IR light is harmless but is highly sensitive to the presence of blood and water molecules in tissue. The molecules in breast tissue absorb certain frequencies of light and scatter others. Near-IR imaging uses special detectors to pick up the near-IR light that is scattered off of tissue. Doctors have used ultrasound for years to pinpoint the exact location of foreign masses in breast tissue and determine whether they are harmless cysts or solid lesions. But ultrasound cannot determine whether the lesions are benig
