An Early Warning of Cancer? (IMAGE) Washington University in St. Louis Caption One of the most exciting uses of photoacoustic tomography is to measure oxygen metabolism, a marker for cancer that may permit much earlier diagnosis than is now possible. In this example, melanoma tumor cells were injected into a mouse ear on day one. By day seven, there were noticeable changes in the blood flow rate (top graph, right), and the metabolic rate of oxygen usage (bottom graph, right). Counterintuitively, the tumor did not increase the oxygen extraction fraction (middle graph). MT stands for melanoma tumor and VD for vasodilation. The colors correspond to depth, with blue being superficial and red deep. Credit Junjie Yao/Lihong Wang Usage Restrictions Credit required License Licensed content 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.