Diffuse Optical Monitoring of Brain and Breast

Summary form only given. The aim of this tutorial is to teach the roots of diffuse optics and then show how this qualitatively different approach to “optics” is finding application in medicine. A long introduction will offer a coherent discussion about light transport in tissue-like turbid media. In particular, we will move quickly from traditional absorption and scattering phenomena in optically thin media to the transport equation and then to the diffusion models for light, including boundary conditions, spectroscopy, and basics of tomography. Transport of both light fluence rate and light correlations will be described. Many excellent primary papers and reviews have been written about this subject matter, and I will cite them in my tutorial, but my introduction is largely based on materials in references [1-7]. After this introduction about light and correlation transport in turbid media, broadly defined, I will focus on what one can learn about tissue hemodynamics by using these tools: blood volume, blood oxygenation, and blood flow. This diagnostic information will lead naturally to models for metabolism and autoregulation, which I will be introduce. Finally, all of the methods discussed above will be demonstrated using clinical and pre-clinical examples drawn primarily from my laboratory, e.g., [8-14]. Sometimes the clinical applications have benefited from recent technical advances [15]. Throughout, I will point out these technical advances, as well as where opportunities exist for diffuse optic technologies.