Hyperpolarized xenon has a much longer relaxation time than protons, which means that the enhanced MRI signal is not only stronger, but lasts much longer. The MRI signal obtained directly from the xenon biosensors is hundreds of times smaller than the easily detected signal obtained from a pool of free xenon dissolved in the rest of the sample. The HYPER-CEST images are based on the free xenon signal rather than direct detection of the biosensors which leads to the high sensitivity of the technique.
Another huge advantage, as Lowery explained, is that "there is no xenon naturally present in body, so we don't have to fish out a small change in an MRI signal with a high background like other MRI contrast agents. In that sense, HYPER-CEST is more like a PET (Positron Emission Tomography) probe. Because multiple xenon biosensors can be used to detect different targets at the same time, HYPER-CEST is also like quantum dots, where different colors of dots can be used to simultaneously report different analytes. However, unlike quantum dots, our xenon agents can be detected deep within the body."