SACRAL PNEUMATOCYSTS - CT APPEARANCE

Objective: CT findings of pneumatocyst of the sacrum have been evaluated. Materials and Methods: Eight patients, six men and two women, with pneumatocysts of the sacrum were studied. Selective CT with 4 and 2 mm thickness was performed, and the intralesional attenuation coefficients were measured. Results: All patients showed subchondral pneumatocysts of the sacrum with esclerotic margins related to the synovial portion of the sacroiliac joint. Intraarticular gas was found in six cases, and evidence of communication between the lesion and the joint was observed in two patients. Signs of bone degeneration were present in all cases. Conclusion: Pneumatocyst of the sacrum is a benign bone lesion associated with arthritic changes.