67-year-old female with erythema, pain, drainage of prior right great toe amputation site, concern for osteomyelitis. Evaluate for osteomyelitis of the right great toe. There is diffuse soft tissue edema particularly along the dorsum of the forefoot which extends into the toes. Patient has undergone amputation of the great toe through the base of the proximal phalanx. Small foci of signal void in the adjacent soft tissues likely reflects suture material. There is a small thin linear focus of increased signal intensity on T2 weighted images that extends from the distal skin surface of the amputation margin to the medial aspect of the proximal phalanx which may represent a small sinus tract, but the remaining base of the proximal phalanx maintains its normal fat signal intensity on T1-weighted images arguing against osteomyelitis. There is increased signal intensity on T2-weighted images circumferentially within the outer margin of the outer head of the first metatarsal with corresponding enhancement on postcontrast images, however on T1 weighted images the fat signal is maintained again arguing against osteomyelitis. There is also increased signal intensity on T2-weighted images and enhancement on postcontrast images concentrated within the medial aspects of both sesamoid bones; there is associated mild decreased signal intensity on T1 weighted images in an ill-defined hazy pattern, and while it is impossible to exclude osteomyelitis, we favor reactive osteitis based on the signal intensity pattern and lack of definite adjacent ulceration. Note is made of a mildly retracted flexor hallucis longus tendon. Mild degenerative arthritic changes affect the forefoot.
Soft tissue edema and postoperative changes as described above. Signal abnormality and enhancement of the first metatarsal head and sesamoid bones is favored to represent reactive osteitis rather than osteomyelitis.