Fig. 2

Preoperative MRI of the lumbar spine without and with intravenous contrast. T2-weighted MRI in the sagittal and axial planes showed a posterior epidural mass extending from the left past the midline to the contralateral posterior side (a and c). Fat-suppressed T1-weighted MRI in the sagittal and axial planes showed a lesion with a heterogeneous ring-like enhancement at the L3 level and demonstrated a sequestered fragment with posterior and superior migration in the dural sac (b and d)