Figure 3. T2-weighted MR images of the left proximal tibia of the same patient in coronal (a) and sagittal (b) planes: They show a well-defined hyperintense lesion in the metaphysis of tibia with a surrounding rim of hypointensity. At the periphery is a surrounding zone of increased signal intensity representing marrow edema

From

The "Penumbra Sign" on Magnetic Resonance Images of Brodie's Abscess: A Case Report and Literature Review

Farate A, Yunusa GH, Umar UH, Ahmadu MS, Mustapha Z, Ahidjo A

American Journal of Medical Case Reports. 2017, 5(8), 199-201 doi:10.12691/ajmcr-5-8-1