Li-Fraumeni Syndrome (LFS) is a cancer predisposition disorder in which most affected individuals develop cancer during their lifetime. The majority of LFS patients carry a mutation in a gene called TP53, whose normal function is to control cell growth and prevent cells with damaged DNA from becoming cancerous. There is currently no way to determine when, where or what type of tumour will develop. This project will use novel techniques utilizing magnetic resonance imaging (MRI) to determine how sensitive they are at detecting very small tumors and how specific they are in terms of distinguishing malignant tumors from benign tumors.