Adjuvant MRI-guided percutaneous cryoablation treatment for aneurysmal bone cyst.

Aneurysmal bone cysts are benign, expansile, lytic bone lesions that behave in a locally aggressive manner. Although radiography and computed tomography (CT) can detect the lesion, magnetic resonance imaging (MRI) is ideal for the demonstration of characteristic fluid-fluid levels, extent, and margins. Treatment typically consists of open surgical curettage with the addition of local adjuvants and bone grafting. Residual or recurring lesions may be treated using percutaneous cryoablation. Although CT guidance is often employed for image guidance, visualization and targeting of smaller clusters can be challenging in young children, secondary to the partially mineralized bone matrix in the immature skeleton. In such cases, the higher contrast resolution of interventional MRI affords direct visualization and targeting of small aneurysmal bone cysts, accurate monitoring of the extent of the growing ice ball beyond the lesion's margin, and avoidance of exposure to ionizing radiation. We report a case of a 5-year-old boy with recurrent or remaining aneurysmal bone cysts of the scapula after surgical excision and embolization, which were successfully treated using MRI-guided cryoablation.