Interstitial fluid transports nutrients and removes waste between the organs and tissues in our body. In the brain, interstitial fluid is thought to be composed of circulating cerebrospinal fluid, cellular waste and blood plasma, and past research has shown a link between interstitial fluid flow and an increased invasion rate of glioblastoma, or brain tumor, cells. A team of biomedical researchers and electrical engineers from the University of Virginia and Virginia Tech recently developed a new method to measure and reconstruct interstitial fluid flow velocities in the brain.