[Etiology of osteonecrosis and bone marrow edema].

Background: The frequent use of magnetic resonance imaging (MRI) introduced "bone marrow edema" (BME) as a descriptive radiological term for hyperintense signal changes in fluid-sensitive sequences. With the optimization of MRI soft tissue contrast, BME has evolved into a valid prognostic indicator associated with pain genesis, trauma, mechanical overload, and progressive cartilage and joint destruction.

Diagnostics: Both osteonecrosis and BME manifest in early MRI as intraosseous fluid accumulation, characterized by hyperintense signals in T2-weighted and STIR sequences.