Photon migration is the process by which light travels through soft tissues and is scattered and absorbed by different components within the tissue, including cells, organelles, and extracellular fluid. The scattered light can then be detected and used to create images of the tissue’s internal structure, a technique known as diffuse optical imaging.

Photon migration is used in a variety of medical applications, including imaging and diagnosis of conditions such as breast cancer, brain tumors, and peripheral vascular disease. By shining light into the tissue and measuring the scattered light that comes back out, physicians can get a better understanding of the tissue’s internal structure and detect abnormalities or changes in the tissue’s composition.

One commonly used technique for photon migration is called diffuse optical spectroscopy and imaging (DOSI), which uses near-infrared light to measure the absorption and scattering of photons in tissue. This technique can provide information about the concentration of oxygenated and deoxygenated haemoglobin, as well as other tissue components, such as water and lipids. DOSI is non-invasive and can provide real-time information about tissue physiology, making it a useful tool for clinical applications.