A case of necrotizing fasciitis caused by coagulase-negative staphylococcus: utility of magnetic resonance imaging for the preoperative diagnosis of necrotizing fasciitis.

A 70-year-old woman presented with fever and pain in the right lower extremity. Fat-suppressed gadolinium-enhanced T1-weighted magnetic resonance imaging (MRI) showed contrast-enhanced fascia, fluid accumulation, and hypointense signals in the muscles. Surgical interventions including incisions and insertion of drainage tubes were performed on the basis of the MRI findings. The histopathological examinations of surgically obtained biopsy specimens demonstrated suppurative fasciitis, widespread myonecrosis, and thromboses of the vessels, all of which were compatible with a diagnosis of necrotizing fasciitis. The bacterial cultures were positive for a coagulase-negative staphylococcus. Following the surgical interventions, the patient was successfully treated by aggressive antimicrobial therapy. MRI can thus be useful for differentiating necrotizing fasciitis from nonnecrotizing soft tissue infection and for planning the treatment of necrotizing fasciitis.