What are the deferential diagnosis?
Osteoid osteoma, osteoblastoma, Brodie's abscess and bone island.
How to differentiate between osteoid osteoma and osteoblastoma?
Mainly by the size. Osteoid osteoma typically 1 cm or smaller, while osteoblastoma is usually larger than 2 cm.
This is a multi sequential MRI which shows focal area of low T1 and T2 signal intensity related to sclerosis in the left pedicle of L5. There is a central area of high signal intensity within the sclerotic area which shows enhancement post contrast administration. Bone edema is also noted, especially on T2FS sequence.