The presence of skeletal muscle edema (increased high T2/STIR signal) on MRI carries an extremely broad differential.
Potential diagnoses include:
-
trauma
effects of direct injury or tear
denervation injury: denervation changes in muscles
early myositis ossificans
-
inflammatory myopathies
-
overlap myositis (myositis associated with connective tissue diseases)
infective myositis including pyomyositis and viral myositis
inherited myopathies (e.g. Duchenne muscular dystrophy, sarcoglycanopathies, or dysferlinopathies)
infiltrating neoplasm, e.g. muscle lymphoma
acute or subacute phase of autoimmune neuropathy, e.g. Parsonage-Turner syndrome (in the shoulder)
-
drug-induced
intravenous heparin therapy
trauma
burns
toxins
autoimmune inflammation
-
vascular causes
-
microvascular disease, e.g. diabetes mellitus
sickle cell crisis
-
-
overuse