MRI is the technique of choice to analyze the bone marrow. It is essential to understand the normal composition and distribution of bone marrow and the changes that occur with age, as well as other physiologic factors that can affect those signals. The normal distribution of red and yellow marrow in the skeleton changes with age in a predictable sequence. It is mandatory to understand the standard and advanced techniques such as diffusion and DIXON to perform an accurate evaluation of bone marrow from a physiologic process such as reconversion through an infiltration process.