ABSTRACT
Introduction ....................................................................................................................................159 Technique .......................................................................................................................................159 Cellulitis/Soft-Tissue Edema .........................................................................................................160 Subcutaneous Abscess....................................................................................................................160 Septic Tenosynovitis ......................................................................................................................160 Septic Arthritis ...............................................................................................................................160 Marrow Edema...............................................................................................................................165 Osteomyelitis..................................................................................................................................168 Neuropathic Change.......................................................................................................................173 Summary ........................................................................................................................................176 References ......................................................................................................................................177
Assessment of possible infection in the foot and ankle is a common reason to obtain an MR (magnetic resonance) examination. In nondiabetic patients infection is commonly secondary to penetrating trauma, postsurgical sequelae, or hematogenous spread. Infection in the diabetic foot is usually secondary to local soft-tissue infection and remains a difficult diagnostic challenge.1 MR imaging is of proven value in the assessment of infection in the ankle and foot.2-7 Although MR imaging shows superb soft-tissue and marrow resolution, the signal changes are not specific. In particular, changes in the marrow may be due to osteomyelitis but also can be reactive marrow edema secondary to infection, trauma, infarction, or neuropathic change, among other entities.
