Respiratory revolved 4D-MRI is used to quantify patient-specific respiratory motion to ensure optimal dose delivery in the radiation therapy of abdominal tumors. In this work, we developed a 4D-MRI technique using 3D k-space encoding, respiratory motion self-gating, and compressive sensing image reconstruction. The proposed 4D-MRI technique could provide high resolution, high quality, respiratory motion resolved 4D images with good soft-tissue contrast and are free of the “stitching” artifacts usually seen on 4D-CT, which is the current clinical standard. Results from motion phantom, healthy volunteers in a 1.5T diagnostic scanner and liver cancer patient in a 0.35T MRI-guided radiation therapy system demonstrated the feasibility of using the proposed 4D-MRI in radiation treatment planning.
