MRI evaluation of bone marrow changes in the diabetic foot: a practical approach.

One of the most important roles of magnetic resonance (MR) in imaging of the diabetic foot is to differentiate between the common and often comorbid pathologies that present with abnormal bone marrow signal. The primary diagnostic challenges in this setting are to distinguish osteomyelitis from reactive bone marrow edema, neuroarthropathy from osteomyelitis, and the sterile from the superinfected neuropathic joint. Whereas both osteomyelitis and reactive marrow edema share increased T2 signal, osteomyelitis is confirmed by T1 hypointensity in the bone marrow and reactive edema demonstrates isolated T2 signal hyperintensity.