3-year-old female patient with right leg pain. There is a 5 x 3.9 x 0.9 cm complex, enhancing collection arising in the soft tissues just superficial to the lateral malleolus and extending proximally. Within this collection, there is a 1.1 x 0.7 cm low signal region compatible with abscess formation with surrounding phlegmonous inflammatory change. This appears to track to a region of eroded fibular cortex and communicates with the medullary bone of the fibula. Low T1, high T2 signal, and enhancement within the entire fibula, excluding the proximal epiphysis, is compatible with osteomyelitis. Extensive edema and enhancement of the musculature of the lower leg is consistent with inflammation. The marrow signal within the tibia is within normal limits. Increased T2 signal within the talus with preservation of T1 signal argues again osteomyelitis and favors reactive osteitis. Multilevel fracturing of the fibular cortex is better evaluated on prior radiographs.
Right fibular osteomyelitis with soft tissue abscess formation.