Researchers at the the University of Michigan are conducting a research project to assess how a course of radiation therapy changes the way blood flows through the liver. To be able to do this, the researchers will be using MRI (magnetic resonance imaging) scans completed before, during, and after radiation therapy. MRI's will be done on 4 or 5 occasions. On each occasion, you will be injected with a fluid called gadolinium (a contrast agent) before getting an MRI. This contrast agent makes it easier for the Researchers to see your organs in the scans, and causes any abnormal areas to become very bright on the MRI. This agent will be injected into a vein in your arm or leg. Each MRI scan will last approximately 45 minutes.