PNEUMATOCYSTS JUXTAARTICULAR TO THE SACRO ILIAC JOINT

Purpose: The purpose of the study was to detect and safely diagnose pn eumatocysts by means of computed tomography. Methods: From September 1 995 to May 1996 computed tomography of the pelvis was performed in six patients for various indications. A slice thickness of 8 mm was emplo yed for all studies. One patient had undergone surgery for hyperparath yroidism nine years previously. Attenuation values within the coincide ntally diagnosed pneumatocysts were obtained. Results: We found a tota l of 14 pneumatocysts juxtaarticular to the sacroiliac joint, Three pa tients demonstrated a bilateral intraarticular vacuum phenomenon, yet a joint communication was not found. The lesions did not coincide with inflammation, tumour or trauma. Conclusion: Pneumatocysts are benign bone lesions associated with arthrotic changes of the sacroiliac joint . Computed tomography is the modality of choice for the diagnosis of p neumatocysts.