intraossäre Zyste mit Lufteinschluss

nicht verwechseln mit: emphysematöse Osteomyelitis

Intraosseous pneumatocysts are gas-containing cystic structures seen inside the bone.


They are of uncertain etiology. These cysts do not communicate with the joint.


Most common site of involvement is sacroiliac joints. Other sites involved are cervical spine, scapula and other bones rarely.

Radiographic features


Appear as very low density (i.e. air at approximately -1000 HU) cystic lesion with thin sclerotic margin, usually abutting a joint.


Low signal intensity on both T1 and T2 weighted MR images.

Differential diagnosis

Imaging differential considerations include:

Practical points

  • There is a risk of erroneously misdiagnosing intraosseous lipomas as intraosseous pneumatocysts, or vice-versa, if the lesion is only eye-balled on a soft tissue window. Therefore if unsure, one should either measure an ROI of the lesion to clarify if gas or fat density, or review the lesion on a lung window.

See also

Siehe auch: