Recently has been demonstrated that bone marrow oedema might be a prognosis marker for OA (osteoarthritis) and inflammatory disease, and could be used as a powerful predictive tool for treatment options. Therefore our role as radiologist is to try to increase specificity to help patient management and decrease progression. The aim of this refresher course is to describe MR imaging features of bone marrow edema in different important and frequent disorders: osteoarthritis, inflammatory diseases and trauma.