Bone marrow edema (BME) is a sign of bone matrix edema, fibrous tissue proliferation, and inflammatory cell infiltration as the main pathological manifestations. It is commonly seen on MRI after joint trauma, and is common in the femur and tibia. What is the test for bone marrow edema? Because bone marrow edema has no morphological changes such as bone contour and cortical fracture, X-ray plain film and CT have great limitations for the diagnosis of bone marrow edema. MRI is the best means to diagnose and evaluate bone marrow edema because of its high sensitivity and specificity, and can provide clinical information for diagnosis and treatment. The normal bone marrow cavity contains more fat particles, T1WI, T2WI are high signal, FE-T2WI and STRI-T2WI bone marrow edema is relatively obvious high signal, so it can accurately diagnose bone marrow edema. STRI-T2WI can find the surrounding soft tissue damage, showing obvious high signal changes. If no abnormality is seen in routine X-ray plain film and CT, and the patient has persistent local pain and swelling, MRI should be performed in time to clarify the existence of occult trauma, otherwise it will delay the condition, aggravate the local bone marrow edema, cause ischemia and hypoxia, microcirculatory disorders, and microfracture of bone trabeculae cannot be repaired in time, which will aggravate the patient’s pain.