Alan McMillan, PhD, an Associate Professor of Clinical Health Sciences in the UW Department of Radiology, was recently awarded a four-year, $1.84 million grant awarded by the National Institute of Biomedical Imaging and Bioengineering (NIBIB) of the National Institutes of Health (NIH) grant for research to study “Improved Techniques for Substitute CT Generation from MRI Datasets” (award number R01-EB026708). Given the greatly improved soft-tissue contrast of MR relative to CT, which aids interpretation of PET in PET/MR and target delineation in radiation treatment planning, a remaining limitation is the current capability to obtain sufficiently accurate substitute CT images from MR-only data. This proposal will enable improved substitute CT images for use in PET/MR and MR-only radiation treatment planning using artificial intelligence and deep learning. Dr. McMillan and his team hope that this project will develop improved approaches for substitute CT images, enabling greater quantitative accuracy and robustness for PET/MR and MR-only radiation treatment planning.