Fig. 2

Patient no. 10, male, 16 years old. Anteroposterior (a) and lateral (b) radiograph demonstrated the increased density in the right attachment of L4 (yellow arrow). CT (c, d) and MRI (e, f) of the lumbar spine represented a 15.4-mm lesion on the right vertebral arch of L4 with typical features of OB (orange arrow). Note the surrounding bone marrow and paraspinal soft tissue edema on T2W (e) and enhanced  T1W/FS sequence (f), a typical finding of OB. The histopathology (g) displayed osteoblast (red arrow), bone-like tissue and woven bone (white arrow), and loose connective tissue rich in dilated small blood vessels (black arrow), indicating a diagnosis of OB