MRI is the preferred method of evaluation for osteomyelitis in the diabetic foot. 1,2,3
In the diabetic foot, osteomyelitis commonly occurs deep to ulcers, hence in the calcaneum, or at the 1st or 5th metatarsophalangeal joints.3 The tarsal bones are a more common site for Charcot's arthropathy than for infection except where there is a rocker bottom foot with ulcer formation secondary to a Charcot arthropathy. An early Charcot arthropathy and osteomyleitis can look very similar. 3
However this patient had clinical infection with repeated blood cultures positive for Staphylococcus aureus, an elevated CRP (194 mg/l) and an elevated white cell count (17.5 x 109/l) with a neutrophilia. In this case specific MRI findings for osteomyelitis and septic arthritis are present, namely cortical hone destruction, bone marrow edema that is markedly low signal on T1 weighted imaging and adjacent rim enhancing fluid collections.