Sagittal T1 MRI without contrast of the knee (left) shows a small round low signal intensity lesion in the middle of the proximal tibia that is surrounded by low signal intensity peri-lesional marrow edema. Sagittal T1 MRI with contrast (center) better demonstrates the small round low signal intensity lesion and coronal T1 MRI with contrast (right) shows a faint enhancing ring (penumbra) around the lesion.
Pediatric Imaging 