Diffuse Optical Spectroscopic Imaging measurements of breast tissue optical properties probe is similar in shape to an ultrasound probe. The imaging can measurements on different areas of the breast including diseased location and normal area. Optical measurements can guided by co-registered ultrasound measurements for the purpose of determining lesion size and location. Each measurement will require about 5-60 seconds to record the data and calculate optical properties. The process will be repeated until an adequate number of measurements are performed and measurements take 30 to 90 minutes.