How the Breast Cancer Optical System Works (image) Columbia University School of Engineering and Applied Science Share Print E-Mail Caption These series of images are cross sections of a breast with a tumor, taken during a breath hold. As a patient holds their breath, the blood concentration increases by up to 10 percent (seen in red). Researchers at Columbia found that analyzing the increase and decrease in blood concentrations inside a tumor could help them determine which patients would respond to chemotherapy. Credit Andreas Hielscher/Columbia Engineering Usage Restrictions Please credit as: Andreas Hielscher/Columbia Engineering Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.