Fig 4.

A 17-year-old boy with low back pack due to a right L4 aneurysmal bone cyst. A, Axial T2-weighted image demonstrates an expansile lesion in the right L4 transverse process, pedicle, and posterior vertebral body with multiple fluid-fluid levels, most compatible with aneurysmal bone cyst. B, Axial CT image during cryoablation of the transverse process portion of the lesion. Note the hypoattenuating ice ball (white arrows) extending beyond portions of the lesion into the soft tissues. A spinal needle (black arrow) was placed into the epidural space for temperature monitoring and carbon dioxide injection (white asterisk) into the epidural space. C, Axial CT image during cementoplasty of the right L4 pedicle and posterior vertebral body components of the lesion. D, Axial T2-weighted image 3 months posttreatment demonstrates near-complete resolution of the expansile component of the tumor (white asterisk) and hypointense cement (white arrow) in the right pedicle and posterior vertebral body.