Osteomyelitis in the setting of a diabetic foot ulcer

(A) Sagittal fluid-sensitive short inversion time inversion recovery (STIR) image demonstrates high signal fluid collection along the plantar surface of the calcaneus (arrow).
(B) Sagittal post-contrast T1-weighted image with fat saturation demonstrates the peripherally enhancing fluid collection (arrow).
(C) Sagittal T1-weighted pre-contrast image demonstrates some cortical interruption (arrow).
(D) Lateral radiograph demonstrates soft tissue loss overlying the plantar aspect of the calcaneus (arrow). Osseous remodeling and periosteal reaction about the posterior calcaneus (asterisk) reflect changes associated with longstanding chronic osteomyelitis.