Brodie abscess

A Brodie abscess is a subacute osteomyelitis, which may persist for years before converting to a frank osteomyelitis. Classically, this may present after conversion as a draining abscess extending from the tibia out through the skin. Occasionally acute osteomyelitis may be contained to a localized area and walled off by fibrous and granulation tissue. This is termed Brodie's abscess.PA view of the left distal tibia showing a lytic lesion in the distal metaphysis with a narrow zone of transition more caudally with a faint sclerotic rim and a wide zone of transition more cephalad. Periostial reaction along the medial cortex indicates an aggressive lesion. Neoplasm such as Ewing sarcoma and osteomyelitis could both have this plain radiographic appearance. Staphylococcus was recovered at surgery.Fat saturated STIR (short tau inversion recovery) image showing hyperintense edema in the calf musculature, marrow edema, and subperiosteal pus. The intramedullary abscess cavity is hyperintense as well.Coronal fat suppressed STIR image showing, bone marrow and subcutaneous edema as well as subperiosteal edema. The thin hypointense rim surrounding the intramedullary collection represents the reactive interface between the abscess and the body's attempt to wall it off.Axial T1-weighted MRI pre-contrast enhancement showing that the intramedullary collection is T1-hyperintense suggesting proteinaceous viscous fluid consistent with infection.Axial T1-weighted fat-saturated MRI image following IV gadolinium contrast demonstrating the intramedullary lytic area seen on radiography to be ring enhancing consistent with a purulent fluid collection. Extensive circumferential periosteal enhancement is noted. There is also substantial bone marrow enhancement.Sagittal T1-weighted fat-suppressed post gadolinium image showing the extent of the multiloculated intramedullary abscess. A Brodie abscess is a subacute osteomyelitis, which may persist for years before converting to a frank osteomyelitis. Classically, this may present after conversion as a draining abscess extending from the tibia out through the skin. Occasionally acute osteomyelitis may be contained to a localized area and walled off by fibrous and granulation tissue. This is termed Brodie's abscess.