The patient had leukocytosis on CBC and elevated ESR and CRP levels. He tested negative for TB.

The patient received antibiotic treatment. The patient improved after antibiotic treatment and his pain resolved.

The penumbra sign is a thin rim of granulation tissue that lines the abscess cavity in cases of subacute osteomyelitis. It has a characteristic of a high signal on unenhanced T1 WI compared to the central hypointense fluid-filled abscess cavity and the surrounding bone marrow edema. It shows an intense post-contrast enhancement.

This rim might appear hyperintense secondary to high protein content similar to cerebral abscesses.