Project Summary. PET (positron emission tomography) is the most sensitive imaging modality available that can be used both for small animals and humans. We propose to build with our industrial and academic partners a new generation of PET scanners based on a single crystal tube (ScintoTube – ST‐PET). This will effectively remove edges from current generation PET scanners. There are distortions at the edges of scanner elements that effectively reduce spatial resolution and sensitivity. The propose scanner has been designed and will be built to be used in a magnetic resonance imaging (MRI) scanner. This is an Academic/Industrial partnership grant. The University of Virginia (UVa) will lead the project. Their partners include i3M (CSIC ‐ Spanish National Research Council) and Bruker Española. The UVa team has expertise in testing/validating novel PET scanners, MRI software (pulse programming) and hardware design, and mouse PET and MRI scanning. I3M and their colleagues at Bruker have a wealth of expertise in designing and building multimodal scanners, including the Albira trimodal PET/SPECT/CT mouse scanner. Much of the technology needed for the ST‐PET scanner has been developed by i3M/Bruker and will be ported as part of this project to the ST‐PET. The proposed work includes: (1) Fabricate a ST‐PET insert for a high field MRI scanner. The insert will be implemented by i3M and Bruker. Test and validate the ST‐PET scanner outside the magnet first at i3M and then at UVa. (2) Integrate and test the ST‐PET insert with the 7T ClinScan MRI at UVa. (3) As a proof‐of‐principle project, use the newly developed ST‐PET/MRI to image lung cancer progression and metastasis in a mouse model.