Intraosseous abscess refers to the pus-filled cavity within the bone with the surrounding rim of granulation tissue 1.
Terminology
The term intraosseous abscess should be used for fluid-signal cavities within the bone showing peripheral rim enhancement, penumbra sign or diffusion restriction in unenhanced images. In subacute or chronic osteomyelitis, the intraosseous abscess could be termed Brodie abscess 1.
Radiographic features
Plain radiograph
lucent lesion with or without surrounding rim of reactive sclerosis often oriented along the long axis of the bone 2,3
periosteal new-bone formation +/- adjacent soft-tissue swelling 2,3
CT
hypodense cystic lesion with thick rim ossification, well-circumscribed periosteal reaction, and reactive bone sclerosis around the lesion 2,3
MRI
T1: hypointense
T2/T2FS/STIR: hyperintense
T1 C+: peripheral enhancement
DWI: diffusion restriction 2,3